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SynC · Historical revision

Boilers

Revision7
EditedOct 2, 2026
StatusSuperseded
Contents

View changes in this revision   Revision history

Historical revision. This is editorial revision 7, kept so citations to it stay resolvable. It is not the current text of this standard — see the current revision.

SynC Standards Team — Specifier (Platform Standards) ✓ OfficialDiscloses employment SynC (SynC Platform Team)
Remade for neutrality: every choice explained, project facts as parameters, scope boundaries linked both ways

1 Scope

1.1 Boundary of Work

NOTE This standard governs the heating boiler as a unit of supply: the pressure vessel and heat exchanger, the burner or electric heating elements, the fuel train from the appliance shutoff valve to the burner, the trim and safety devices mounted on the vessel, the burner management and boiler controls, the combustion air and vent connections, the flue gas condensate drain, and the startup and testing that prove the assembly fires safely at the rated input. (1.1.1)
NOTE The boundary of work begins at the appliance shutoff valve on the fuel gas supply, at the oil supply and return connections on the burner, at the line terminals of the boiler control panel, and at the combustion air inlet, and it ends at the isolation valves on the supply and return or steam and condensate connections, at the vent connector on the boiler flue collar, and at the condensate drain outlet. (1.1.2)
NOTE A boiler under this standard operates within the limits of ASME BPVC Section IV: steam at 15 psig or less, and hot water at 160 psig or less and 250°F or less. Above either limit the vessel is a power boiler constructed to ASME BPVC Section I, and this standard does not apply. (1.1.3)
NOTE The following are governed elsewhere and are outside this standard: (1.1.4)
  • The hydronic distribution piping beyond the boiler isolation valves, its hangers, and its pressure test Hydronic PipingHydronic PipingResolves to the current adopted revision.sync/hydronic-piping
  • Steam and condensate distribution piping, drip legs, traps, condensate receivers, and condensate return pumps Steam And Condensate PipingSteam and Condensate PipingResolves to the current adopted revision.sync/steam-and-condensate-piping
  • Circulating and boiler feed pumps that are not factory-mounted on the boiler HVAC PumpsHVAC PumpsResolves to the current adopted revision.sync/hvac-pumps
  • Expansion tanks, air separators, and automatic air vents Expansion Tanks And Air SeparatorsExpansion Tanks and Air SeparatorsResolves to the current adopted revision.sync/expansion-tanks-and-air-separators
  • The system relief valve on any loop that an isolation valve can separate from the boiler relief valve, together with strainers, balancing devices, and other in-line specialties Hydronic SpecialtiesHydronic SpecialtiesResolves to the current adopted revision.sync/hydronic-specialties
  • General-duty isolation valves at the boiler connections HVAC Piping ValvesGeneral-Duty Valves for HVAC PipingResolves to the current adopted revision.sync/hvac-piping-valves
  • The ongoing water treatment program, feedwater pretreatment, internal treatment, blowdown chemistry, and lay-up HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment
  • Cleaning, flushing, and passivation of the system before the boiler is fired on treated water Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current adopted revision.sync/hydronic-cleaning-and-flushing
  • Fuel gas piping, line pressure regulators, and the appliance shutoff valve and connector Fuel Gas PipingFacility Liquefied-Petroleum and Fuel Gas PipingResolves to the current adopted revision.sync/fuel-gas-piping and Natural Gas PipingNatural Gas PipingResolves to the current adopted revision.sync/natural-gas-piping
  • Fuel oil tanks, transfer pumps, filtration, leak detection, and the supply and return piping to the burner connections Fuel Oil SystemsFacility Fuel-Oil SystemsResolves to the current adopted revision.sync/fuel-oil-systems
  • Steam-to-water and water-to-water heat exchangers served by the boiler plant Heat ExchangersHeat ExchangersResolves to the current adopted revision.sync/heat-exchangers
  • Domestic water heaters, hot water supply boilers serving potable water, and indirect water heaters, including the boiler-fed coil inside them Water HeatersCommercial Water HeatersResolves to the current adopted revision.sync/water-heaters
  • Field-applied insulation of breeching, stacks, and connected piping Mechanical InsulationMechanical InsulationResolves to the current adopted revision.sync/mechanical-insulation
  • The controllers, network, graphics, alarming, and programming of the building automation system Building Automation SystemBuilding Automation SystemResolves to the current adopted revision.sync/building-automation-system
  • System sensors, thermowells, and control valves beyond the boiler-mounted devices HVAC Controls InstrumentationHVAC Instrumentation and Control DevicesResolves to the current adopted revision.sync/hvac-controls-instrumentation
  • Vibration isolation and seismic restraint hardware and its design Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current adopted revision.sync/vibration-isolation-and-seismic-restraint
  • The concrete housekeeping pad Concrete PadsConcrete Equipment PadsResolves to the current adopted revision.sync/concrete-pads
  • Fuel gas and carbon monoxide detection in the boiler room Gas Detection SystemsGas Detection SystemsResolves to the current adopted revision.sync/gas-detection-systems
  • The electrical feeder and disconnecting means upstream of the boiler control panel Enclosed Switches And DisconnectsEnclosed Switches and DisconnectsResolves to the current adopted revision.sync/enclosed-switches-and-disconnects
  • Warm-air furnaces and unit heaters FurnacesFurnacesResolves to the current adopted revision.sync/furnaces and Unit HeatersUnit HeatersResolves to the current adopted revision.sync/unit-heaters
NOTE The capacity, firing rate, number of boilers, design temperatures, and electrical characteristics of each boiler are recorded on the mechanical equipment schedule; this standard governs what the boiler does once those values are set and never selects them. (1.1.5)
1.1.6 The Contractor shall install boilers in the locations shown on the mechanical plans.

1.2 Terms Used in This Standard

NOTE The following terms carry the meanings given here throughout this standard: (1.2.1)
  • Heating medium: the fluid the boiler heats and delivers, either hot water in a closed loop or low-pressure steam
  • Input: the rate at which the boiler consumes fuel or electricity at full fire, expressed in Btu/h or kW
  • Gross output: the rate at which heat is delivered to the heating medium at the rated input
  • Turndown: the ratio of the maximum firing rate to the minimum stable firing rate of a single boiler
  • Condensing boiler: a boiler whose heat exchanger is designed to cool the flue gas below its water dew point and to drain the resulting condensate continuously
  • Vent category: the classification of a gas-fired appliance under ANSI Z21.13 by vent static pressure and by whether the flue gas condenses in the vent
  • Trim: the gauges, relief valve, low-water cutoffs, limit controls, and drain and blowdown valves mounted on the vessel
  • Burner management: the control that sequences purge, ignition, flame proving, run, and shutdown, and that locks out the burner on a safety fault
  • Lockout: a burner shutdown that requires a manual reset before the burner can fire again

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where the contract documents, the Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
2.3 The mechanical code, fuel gas code, and boiler and pressure vessel regulations adopted with Adopted Building CodeAdopted Building CodeParameterEach project supplies its own value.adopted-building-code shall take precedence over every other reference on any matter they address directly.
Standard Title
ASME BPVC Section IV Rules for Construction of Heating Boilers
ASME BPVC Section I Rules for Construction of Power Boilers
ASME BPVC Section VI Recommended Rules for the Care and Operation of Heating Boilers
ASME CSD-1 Controls and Safety Devices for Automatically Fired Boilers
NFPA 85 Boiler and Combustion Systems Hazards Code
NFPA 54 / ANSI Z223.1 National Fuel Gas Code
NFPA 31 Standard for the Installation of Oil-Burning Equipment
NFPA 211 Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances
NFPA 70 National Electrical Code
IMC International Mechanical Code
IFGC International Fuel Gas Code
IECC International Energy Conservation Code
ANSI/ASHRAE/IES 90.1 Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
ANSI Z21.13 / CSA 4.9 Gas-Fired Low-Pressure Steam and Hot Water Boilers
UL 795 Commercial-Industrial Gas Heating Equipment
UL 726 Oil-Fired Boiler Assemblies
UL 296 Oil Burners
UL 834 Heating, Water Supply, and Power Boilers, Electric
UL 441 Gas Vents
UL 641 Type L Low-Temperature Venting Systems
UL 103 Factory-Built Chimneys for Residential Type and Building Heating Appliances
UL 1738 Venting Systems for Gas-Burning Appliances, Categories II, III, and IV
UL 378 Draft Equipment
AHRI 1500 Performance Rating of Commercial Space Heating Boilers
10 CFR Part 431 Subpart E Energy Conservation Program for Certain Commercial and Industrial Equipment, Commercial Packaged Boilers
10 CFR Part 430 Energy Conservation Program for Consumer Products
NBBI NB-23 National Board Inspection Code
ASCE 7 Minimum Design Loads and Associated Criteria for Buildings and Other Structures
FM Global Data Sheet 6-4 Oil- and Gas-Fired Single-Burner Boilers
NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum)

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for review before any boiler is procured:
  • product data for each boiler, giving the heating medium, heat source, combustion technology, heat exchanger configuration and material, input and gross output at the rated condition, the efficiency rating and the metric it is expressed in, turndown, water content, waterside pressure drop at design flow, maximum allowable working pressure, dimensions, operating and shipping weights, and the required service clearances
  • burner product data, giving the burner configuration, firing control, ignition and flame detection method, fuel-air ratio control, published NOx and CO emission ratings at the rated input, and the sound pressure level at the rated input
  • a fuel train schematic for each fuel, showing every valve, regulator, switch, and test connection, with the inlet pressure range the train requires and the code or insurer standard the train is built to
  • a controls and safety device schedule identifying each limit, cutoff, interlock, and relief device, its setpoint or set pressure, its reset type, and the clause of ASME CSD-1 or NFPA 85 it satisfies
  • relief valve selection data, giving the set pressure, relieving capacity, outlet size, and certification mark
  • vent and combustion air data, giving the vent category, the vent materials the boiler manufacturer names for the model furnished, the maximum and minimum equivalent vent length, and the combustion air pipe or opening size
  • condensate neutralizer product data, giving the media type, media volume, and the condensate rate the unit is rated for
  • electrical data, giving voltage, phase, full-load amperes, minimum circuit ampacity, maximum overcurrent protection, and the control power arrangement
  • wiring diagrams showing every factory and field connection, the burner management sequence, and every point made available to the building automation system
  • a plant sequencing description identifying the controller that stages the boilers, the staging and rotation logic, and the supply temperature reset schedule
Action Submittal Packagecheckbox
☐ Boiler product data
☐ Burner product data
☐ Fuel train schematic
☐ Controls and safety device schedule
☐ Relief valve selection data
☐ Vent and combustion air data
☐ Condensate neutralizer product data
☐ Electrical data
☐ Wiring diagrams and BAS point list
☐ Plant sequencing description
3.1.2 Fabrication of boilers shall not begin until the corresponding action submittals have been reviewed and returned.

3.2 Informational Submittals

3.2.1 The Contractor shall submit the following supporting calculations and certifications with, or before, the action submittals:
  • the input derate the boiler requires at the project elevation, with the source of the derate identified
  • vent sizing calculations for each vent and breeching, including the total equivalent length, the fitting allowances used, and the common vent method where more than one boiler shares a vent
  • combustion air calculations for the boiler room, showing the method used and the opening, duct, or pipe size the method yields
  • seismic anchorage calculations sealed by a registered design professional, or the pre-approved anchorage detail the Contractor intends to use, with the detail's listing identified
  • evidence that the boiler model furnished is certified under the federal energy conservation program for its class, where the class is regulated
  • documentation that the startup technician holds the certification required by this standard
  • the emissions compliance statement the air district having jurisdiction requires for the boiler at its rated input, where the district imposes a limit
Informational Submittal Packagecheckbox
☐ High-altitude input derate
☐ Vent and breeching sizing calculations
☐ Combustion air calculations
☐ Seismic anchorage calculations or pre-approved detail
☐ Federal efficiency certification evidence
☐ Startup technician certification
☐ Air district emissions compliance statement

3.3 Closeout Submittals

3.3.1 The Contractor shall submit the following before the boiler plant is accepted:
  • the Manufacturer's Data Report for each boiler on the applicable ASME Section IV form, and the National Board registration number where the boiler is registered
  • the factory hydrostatic test certificate for each pressure vessel, and the factory fire test report where a fire test was required
  • the jurisdictional inspection certificate or operating permit for each boiler, where the Authority Having Jurisdiction issues one
  • the startup report for each boiler, signed by the technician who performed it, recording every setting as found and as left
  • combustion test results for each boiler at high fire, at the lowest stable firing rate, and at two intermediate rates for a modulating burner
  • the safety device test record required by this standard, recording the result of each test and the setpoint verified
  • the as-left burner management and boiler controller configuration, including every parameter changed from the factory value
  • operation and maintenance manuals for the boiler, burner, controls, vent system, and neutralizer, with the recommended maintenance tasks and their intervals tabulated
  • warranty documentation for each boiler, identifying the coverage of the pressure vessel and heat exchanger separately from the balance of the unit, and the date coverage begins
  • a signed receipt from the Owner for the spare parts delivered
Closeout Submittal Packagecheckbox
☐ ASME Manufacturer's Data Reports and National Board numbers
☐ Factory hydrostatic and fire test certificates
☐ Jurisdictional inspection certificate or operating permit
☐ Signed startup reports
☐ Combustion test results
☐ Safety device test record
☐ As-left controls configuration
☐ Operation and maintenance manuals
☐ Warranty documentation
☐ Spare parts receipt

4 Quality Assurance

4.1 Manufacturer Qualifications

4.1.1 Each boiler shall be the product of a manufacturer that has produced boilers of the type, heating medium, and heat source furnished for at least ten years and holds a current ASME Certificate of Authorization for the Section IV H stamp.
4.1.2 The burner, the burner management control, and the boiler shall be furnished as one listed assembly, or, where the burner is furnished by a separate burner manufacturer, the boiler manufacturer shall certify in the submittal that the pairing is approved for the boiler model and input furnished.
NOTE A burner and a boiler that were never fire-tested together can meet their separate listings and still produce a flame that impinges on the heat exchanger, a purge that does not clear the furnace, or an efficiency neither party will stand behind, which is why one party is required to take responsibility for the pairing. (4.1.3)
4.1.4 Replacement parts for the boiler, burner, and controls shall be available from the manufacturer for at least ten years after the date of manufacture.

4.2 Pressure Vessel Code Stamping and Registration

4.2.1 Each boiler pressure vessel shall be designed, fabricated, inspected, tested, and stamped in accordance with ASME BPVC Section IV and shall bear the ASME Certification Mark with the H designator.
4.2.2 Each boiler shall be furnished with a Manufacturer's Data Report on the applicable Section IV form, signed by the manufacturer and by the Authorized Inspector.
4.2.3 National Board registration shall be as indicated in the datasheet.
National Board Registrationradio
● Each boiler registered with the National Board
○ Registration not required
NOTE National Board registration files the Manufacturer's Data Report with a body independent of the manufacturer and the Owner, so the record of how the vessel was built survives a change of ownership or the manufacturer leaving the market; most jurisdictions and most boiler insurers require it, and the few that do not still accept it. (4.2.4)
4.2.5 Where the boiler is registered, the National Board number shall be stamped on the vessel and recorded in the closeout submittals.

4.3 Controls and Safety Device Code

4.3.1 The code governing the controls and safety devices of each boiler shall be as indicated in the datasheet.
Controls and Safety Device Codeselect
ASME CSD-1
NFPA 85
Derived — the rated input of the boiler compared against the ASME CSD-1 input threshold, and any adoption of NFPA 85 by the Authority Having Jurisdiction or the Owner's insurer at a lower input (by default)
NOTE ASME CSD-1 governs automatically fired boilers below its input threshold of 12,500,000 Btu/h, and NFPA 85 governs boilers at or above it; the two set the same kinds of requirements, purge, flame supervision, fuel safety shutoff, limit redundancy, and low-water protection, but NFPA 85 adds the prepurge air flow proving, the vent valve between the safety shutoff valves, and the written commissioning plan that a larger furnace volume justifies. (4.3.2)
4.3.3 The controls, safety devices, fuel train, and burner management sequence of each boiler shall comply with the code indicated in the datasheet.
4.3.4 Where the Owner's property insurer requires an inspection of the installed controls and safety devices, the Contractor shall make the boiler available for that inspection before the boiler is placed in service.

4.4 Product Listing

4.4.1 Each gas-fired boiler shall be certified to ANSI Z21.13 / CSA 4.9 by a Nationally Recognized Testing Laboratory and shall bear the certification mark.
4.4.2 Each gas-fired boiler with an input above the scope of ANSI Z21.13 shall be listed to UL 795 as a commercial-industrial gas heating assembly.
4.4.3 Each oil-fired boiler shall be listed to UL 726 as an oil-fired boiler assembly, with a burner listed to UL 296.
4.4.4 Each electric boiler shall be listed to UL 834.
4.4.5 The electrical components of each boiler shall be listed as part of the boiler assembly, and the control panel shall bear the listing mark of the assembly or a separate industrial control panel listing.

4.5 Installer and Startup Qualifications

4.5.1 Each portion of the installation shall be performed by personnel holding the license the Authority Having Jurisdiction requires for that trade.
4.5.2 Startup of each boiler shall be performed by a technician employed or certified by the boiler manufacturer for the boiler model and burner furnished.
4.5.3 Combustion setup shall be performed by a technician using a combustion analyzer calibrated within the twelve months before the test, and the calibration record shall accompany the startup report.
4.5.4 The Contractor shall have the required licenses and certifications on site and available for inspection before startup begins.

4.6 Jurisdictional Inspection

4.6.1 The Contractor shall obtain the boiler installation permit the Authority Having Jurisdiction requires before the boiler is set.
4.6.2 The Contractor shall arrange the jurisdictional inspection of the installed boiler, its trim, and its safety devices, and shall not fire the boiler for sustained operation until the inspector has released it or the jurisdiction has confirmed in writing that no inspection is required.
4.6.3 The Contractor shall bear the cost of any re-inspection caused by a deficiency in the work under this standard.

4.7 Pre-Installation Conference

4.7.1 A pre-installation conference shall be held before any boiler is rigged into place, attended by the mechanical contractor, the controls contractor, the electrical contractor, the fuel piping contractor, the commissioning authority, the boiler manufacturer's startup representative, and the Owner's representative.
4.7.2 The conference shall settle the rigging route and sequence, the pad and anchorage, the vent and combustion air routing and materials, the fuel connection point and the inlet pressure the train requires, the electrical connection and control power, the condensate drain route, the fill, cleaning, and treatment sequence, the control interface and point list, and the startup and inspection schedule.
4.7.3 The Contractor shall record the decisions of the conference and distribute them to every attendee within seven days.

5 Service Conditions at the Boiler

5.1 Boiler Room and Location

5.1.1 A boiler installed indoors shall be installed in a room that meets the combustion air, clearance, and egress requirements of the adopted mechanical code and fuel gas code for the input furnished.
5.1.2 The boiler room shall be provided with a floor drain or indirect waste receptor able to accept relief valve discharge, blowdown, condensate, and a full boiler drain-down without flooding the room.
5.1.3 Where no gravity receptor can be provided, a sump with a duplex pump shall be provided, alarmed on high level to the building automation interface specified in this standard.
5.1.4 A boiler installed outdoors shall be listed for outdoor installation, furnished with the weatherproof jacket, intake and vent hoods, and control enclosure the listing requires, and protected against freezing of its waterside, its condensate drain, and its trim at Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum.
5.1.5 Freeze protection of an outdoor boiler shall not rely on burner operation alone; the waterside shall be protected by circulation, by heat tracing, or by an inhibited glycol solution the boiler manufacturer accepts.
NOTE A boiler room is a room that can be made negative by the exhaust fans around it, and a burner that draws its air from such a room backdrafts its own flue; the combustion air provisions of this standard exist because the room is part of the combustion system whether or not the drawings treat it that way. (5.1.6)

5.2 Site Elevation

NOTE Combustion equipment loses rated input with elevation, because thinner air carries less oxygen through the same burner at the same fan speed, and a boiler selected at its sea-level rating will not meet its scheduled output at a high-altitude site. (5.2.1)
5.2.2 Each fuel-fired boiler shall be derated and configured for AltitudeAltitudeParameterEach project supplies its own value.altitude in accordance with the boiler manufacturer's published high-altitude data, or in accordance with NFPA 54 where the manufacturer publishes none.
5.2.3 Where the manufacturer supplies a high-altitude orifice, fan setting, or firmware configuration for the project elevation, it shall be installed at the factory or by the startup technician and recorded in the startup report.
5.2.4 The scheduled gross output shall be met at the project elevation after derate, not at sea level.

5.3 Control Enclosure Rating

5.3.1 The enclosure rating of the boiler control panel shall be as indicated in the datasheet.
Control Panel Enclosure Ratingselect
NEMA Type 1
NEMA Type 2
NEMA Type 3R
NEMA Type 4
NEMA Type 4X
NEMA Type 12
NOTE Type 1 is the general-purpose indoor enclosure and the norm for a conditioned boiler room; Type 2 adds a drip shield for a room where piping overhead can drip; Type 3R sheds rain and is the outdoor minimum; Type 4 and 4X are hose-tight, with 4X adding corrosion resistance for a coastal or chemical atmosphere; and Type 12 excludes dust and dripping oil in an industrial room without washdown. (5.3.2)
5.3.3 The control panel of a boiler installed outdoors shall be rated NEMA Type 3R at minimum.
5.3.4 The control panel of a boiler installed where it is exposed to hose-directed water shall be rated NEMA Type 4 at minimum.
5.3.5 The control panel of a boiler installed in a corrosive atmosphere, including a coastal location exposed to salt spray or a room where treatment chemicals are stored open, shall be rated NEMA Type 4X.
5.3.6 Enclosure ratings shall be as defined in NEMA 250.

6 Heating Medium and Heat Source

6.1 Heating Medium

6.1.1 The heating medium shall be as indicated in the datasheet.
Heating Mediumradio
● Hot water
○ Low-pressure steam
NOTE Hot water carries heat at lower temperature and pressure, modulates readily with variable flow, and condenses flue gas when the return is cool enough; steam carries far more heat per pound, needs no pump to move it, and serves humidifiers, sterilizers, and kitchen equipment that hot water cannot, at the cost of condensate return, feedwater control, a boiler that cannot condense, and a treatment program for carbonic acid in the return. (6.1.2)
6.1.3 Where the datasheet selects low-pressure steam, the requirements of the Steam Boiler Trim and Feedwater Control article of this standard apply in addition to the requirements for every boiler.

6.2 Heat Source

6.2.1 The heat source shall be as indicated in the datasheet.
Heat Sourceselect
Natural gas
Propane
No. 2 fuel oil
Dual fuel, natural gas and No. 2 fuel oil
Dual fuel, natural gas and propane
Electric resistance
Electric electrode
NOTE Natural gas is the lowest-cost fuel where a utility main reaches the site and the only fuel that condensing technology is widely built around; propane serves a site without gas service at a higher fuel cost and with a tank and vaporization capacity that the fuel gas work must provide; No. 2 oil serves a site without gas and is the common standby fuel where the gas tariff is interruptible, at the cost of storage, a two-pipe burner supply, and stricter emissions scrutiny; a dual-fuel burner fires gas by default and oil or propane when gas is curtailed, which some interruptible tariffs require; electric resistance avoids combustion, venting, and emissions entirely and is favored where the electric rate or an electrification policy supports it, with capacity limited by the electrical service; and an electrode boiler reaches very large capacities in a small footprint by passing current through the water itself, which ties its output to water conductivity and usually to a medium-voltage supply. (6.2.2)
6.2.3 Where the datasheet selects natural gas, the Contractor shall confirm that Site Natural Gas ServiceSite Natural Gas ServiceParameterEach project supplies its own value.site-natural-gas-service delivers the inlet pressure and the full-fire input of the plant at the appliance shutoff valve, and shall report any shortfall before the boiler is ordered.
6.2.4 Where the datasheet selects propane, the boiler shall be furnished with the orifices, pressure settings, and controller configuration for propane installed at the factory or by the startup technician, and the vapor demand of the plant at full fire shall be furnished to the fuel gas work under Fuel Gas PipingFacility Liquefied-Petroleum and Fuel Gas PipingResolves to the current adopted revision.sync/fuel-gas-piping for vaporization capacity.
6.2.5 Where the datasheet selects an oil fuel, the burner's required supply pressure, return pressure, and flow at the burner connections shall be furnished to the fuel oil work under Fuel Oil SystemsFacility Fuel-Oil SystemsResolves to the current adopted revision.sync/fuel-oil-systems before the oil piping is designed.
6.2.6 Where the datasheet selects an electric heat source, the requirements of the Electric Boilers section of this standard apply in addition to the requirements for every boiler.

6.3 Combustion Technology

6.3.1 The combustion technology shall be as indicated in the datasheet.
Combustion Technologyradio
○ Condensing
○ Non-condensing
○ Not applicable to the selected heat source
NOTE A condensing boiler recovers the latent heat of the water vapor in the flue gas by cooling the gas below its dew point, which for natural gas falls near 130°F, so its efficiency rises as the return water gets cooler and falls to that of a non-condensing boiler on a loop whose return never drops below the dew point; it buys that efficiency with a corrosion-resistant heat exchanger, an acidic condensate drain, and a positive-pressure vent. A non-condensing boiler keeps its flue gas above the dew point, tolerates high loop temperatures, vents through conventional materials, and needs its return water held above the manufacturer's minimum so that the condensate it is not built for never forms on its heating surface. (6.3.2)
NOTE A steam boiler is non-condensing by the nature of its service, because the steam-side temperature holds the flue gas above its dew point. (6.3.3)
6.3.4 Where the datasheet selects a condensing boiler, the scheduled design return water temperature shall be low enough to condense at the plant's part-load operating points, or the Engineer of Record shall record in the contract documents that the selection was made on another basis.
6.3.5 Where the datasheet selects a non-condensing boiler, the return water temperature protection required by the Water Flow Through the Boiler article of this standard shall be provided.

7 Capacity and Plant Arrangement

7.1 Scheduled Capacity

NOTE Input, gross output, water flow, and the number of boilers are the outputs of the Engineer's heating load calculation and plant design, recorded on the mechanical equipment schedule; this standard governs what the boiler must do once those numbers are set. (7.1.1)
7.1.2 The rated input of each boiler shall be as indicated in the datasheet.
Rated Inputrange
MBH
50100150200300400500750100015002000250030004000500060008000100001250015000200002500030000400005000060000
Per drawings — the mechanical equipment schedule (deferred by default)
7.1.3 The gross output of each boiler shall be as indicated in the datasheet.
Gross Outputrange
MBH
40801201602403204006008001200160020002400320040004800640080001000012000160002000024000320004000050000
Per drawings — the mechanical equipment schedule (deferred by default)
7.1.4 The design water flow through each hot water boiler shall be as indicated in the datasheet.
Design Water Flow per Boilerrange
GPM
25102030507510015020030040050075010001500200030005000
Per drawings — the mechanical equipment schedule (deferred by default)
7.1.5 The Contractor shall confirm that the gross output of the boiler model furnished, at the project elevation and at the scheduled supply and return temperatures, equals or exceeds the scheduled gross output, and shall report any shortfall before the boiler is ordered.
7.1.6 The Contractor shall confirm that the waterside pressure drop of the boiler model furnished at the scheduled flow is within the head the pump selection under HVAC PumpsHVAC PumpsResolves to the current adopted revision.sync/hvac-pumps allows for the boiler, and shall report any excess before the boiler is ordered.

7.2 Number of Boilers and Redundancy

7.2.1 The number of boilers in the plant shall be as indicated in the datasheet.
Number of Boilersrange
124
Per drawings — the mechanical equipment schedule (deferred by default)
7.2.2 The redundancy basis of the plant shall be as indicated in the datasheet.
Plant Redundancy Basisselect
A single boiler carrying the full load
Multiple boilers sharing the load with no standby capacity
Multiple boilers with one boiler of standby capacity beyond the design load
Multiple boilers each sized for the full load
NOTE A single boiler is the least first cost and the only arrangement with no redundancy, and it runs at a small fraction of its capacity for most of the heating season; multiple boilers sharing the load without standby spread the turndown across the plant and lose part of the capacity when one is down; one boiler of standby capacity holds the full design load with any one boiler out of service at the cost of one more boiler and its vent and fuel connections; and boilers each sized for the full load give the highest availability at the highest first cost and the poorest part-load match unless each boiler has deep turndown. (7.2.3)
7.2.4 Where the datasheet selects an arrangement with standby capacity, the plant sequencing shall rotate the lead boiler on a schedule the Owner can adjust, so that no boiler stands idle for a full season.
7.2.5 Where the datasheet selects an arrangement with standby capacity, the sequencing controller shall start the standby boiler automatically on failure or lockout of a running boiler.

7.3 Operating Temperatures and Pressures

7.3.1 The design supply water temperature of a hot water boiler shall be as indicated in the datasheet.
Design Supply Water Temperaturerange
°F
90100110120130140150160170180190200210220230240250
Per drawings — the mechanical equipment schedule (deferred by default)
7.3.2 The design return water temperature of a hot water boiler shall be as indicated in the datasheet.
Design Return Water Temperaturerange
°F
60708090100110120130140150160170180190200220240
Per drawings — the mechanical equipment schedule (deferred by default)
7.3.3 The maximum allowable working pressure of a hot water boiler shall be as indicated in the datasheet.
Maximum Allowable Working Pressurerange
psig
304550607580100125150160
Derived — the system working pressure at the boiler connection, including static head and pump head, with the fill and expansion pressures coordinated under [[sync/expansion-tanks-and-air-separators]] (by default)
7.3.4 The operating steam pressure of a steam boiler shall be as indicated in the datasheet.
Operating Steam Pressurerange
psig
0.512357101215
Per drawings — the mechanical equipment schedule (deferred by default)
7.3.5 The maximum allowable working pressure of each boiler shall equal or exceed the pressure the system imposes at the boiler connection with the pumps running and the expansion tank at its highest operating pressure, and shall not exceed the Section IV limit for the heating medium.
7.3.6 The boiler rated maximum water temperature shall equal or exceed the design supply water temperature plus the differential of the operating control, and shall not exceed 250°F.
NOTE A boiler whose rated pressure is only just above the system's working pressure relieves on every pressure excursion, and a boiler rated far above it costs more for no benefit; the derived basis points the selection at the number the system actually produces rather than at a catalog maximum. (7.3.7)

8 Efficiency and Turndown

8.1 Efficiency Rating

NOTE The federal energy conservation program, ASHRAE 90.1, and the adopted energy code each set an efficiency floor for a boiler class, each in the metric that class is tested under; the boiler must clear whichever floor is highest, and a rating in a different metric cannot be compared against it. (8.1.1)
8.1.2 Each boiler shall meet or exceed the highest applicable minimum efficiency imposed by 10 CFR Part 431 Subpart E or 10 CFR Part 430, by ANSI/ASHRAE/IES 90.1, and by Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code for its heating medium, heat source, and input.
8.1.3 The metric in which efficiency is expressed and verified shall be as indicated in the datasheet.
Efficiency Rating Metricselect
Annual fuel utilization efficiency
Thermal efficiency
Combustion efficiency
Not applicable to an electric boiler
Derived — the rated input and heating medium of the boiler and the federal test procedure that class falls under (by default)
NOTE Annual fuel utilization efficiency applies to residential-class boilers below the commercial input threshold and folds cycling and standby losses into a seasonal figure; thermal efficiency applies to commercial packaged boilers up to the upper size the federal program tests at steady state, and counts jacket losses; combustion efficiency applies to the largest boilers and is measured from the flue gas alone, so it reads higher than thermal efficiency on the same boiler. (8.1.4)
8.1.5 The minimum efficiency of each fuel-fired boiler shall be as indicated in the datasheet.
Minimum Efficiencyrange
%
757880828384858687889092949596979899
Derived — the boiler class and the highest of the federal, ASHRAE 90.1, and Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code minimums in force for that class at the date of manufacture, in the efficiency rating metric indicated in the datasheet (by default)
8.1.6 Efficiency ratings for commercial packaged boilers shall be established in accordance with AHRI 1500 and the federal test procedure, and the certified rating of the model furnished shall be stated in the submittal.
NOTE A condensing boiler's certified rating is measured at a return temperature low enough to condense, and the boiler delivers that rating only when the loop supplies such a return; the Contractor's startup report records efficiency at the loop's actual return temperature, which is the number the Owner will see. (8.1.7)

8.2 Burner Turndown

8.2.1 The minimum turndown of each fuel-fired boiler shall be as indicated in the datasheet.
Minimum Burner Turndownrange
:1
123456810121520253040
Derived — the plant redundancy basis, the smallest load the plant must carry without cycling, and the minimum turndown Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code requires at the plant's design input (by default)
NOTE A turndown of 1 is an on-off burner. Deeper turndown lets one boiler follow a small load without cycling, and each cycle avoided saves the purge that sends a furnace volume of heated air up the stack and the thermal shock a cold start puts on the heat exchanger; in a plant of several boilers the plant turndown is the product of the staging and the per-boiler turndown, so a plant of four boilers at 5:1 turns down to 20:1 while a single boiler needs the whole range by itself. Deep turndown costs more in burner and controls, raises excess air at low fire on some burner designs, and narrows the stable range at altitude. (8.2.2)
8.2.3 The minimum stable firing rate of each boiler shall be demonstrated at startup with the combustion readings within the manufacturer's published range, and a boiler that cannot hold stable combustion at the turndown indicated in the datasheet shall be corrected or replaced at no cost to the Owner.

9 Heat Exchanger and Pressure Vessel

9.1 Heat Exchanger Configuration

9.1.1 The heat exchanger configuration shall be as indicated in the datasheet.
Heat Exchanger Configurationselect
Fire-tube
Water-tube
Cast-iron sectional
Cast-aluminum sectional
Copper finned-tube
Stainless steel coil or helical
Electric immersion element vessel
NOTE A fire-tube boiler passes the flue gas through tubes surrounded by water, holds a large water volume, tolerates low flow and load swings, and is the common form of the largest hot water and steam boilers; a water-tube boiler passes the water through tubes surrounded by flue gas, holds little water, responds fast, and needs a dependable minimum flow; a cast-iron sectional boiler is assembled from sections that pass through a doorway and can be replaced one at a time, serves non-condensing duty, and tolerates the water chemistry of an old system; a cast-aluminum sectional boiler brings the sectional form to condensing duty with a light casting that is sensitive to water pH; a copper finned-tube boiler is compact, low mass, and non-condensing, with a tight minimum flow and the lowest tolerance of scale; a stainless coil or helical exchanger is the common compact condensing form, with a single water path that makes low flow and debris the failure modes; and an electric immersion element vessel has no flue gas side at all. (9.1.2)
9.1.3 The heat exchanger configuration furnished shall be one the boiler manufacturer lists for the combustion technology and heating medium indicated in the datasheet.

9.2 Heat Exchanger Material

9.2.1 The material of the heating surface in contact with flue gas shall be as indicated in the datasheet.
Heat Exchanger Materialselect
Stainless steel Type 316L
Stainless steel Type 439
Stainless steel Type 444
Duplex stainless steel
Aluminum-silicon alloy
Cast iron
Carbon steel
Copper
Not applicable to an electric boiler
NOTE Austenitic Type 316L resists the carbonic and sulfurous acids in flue gas condensate and is the most forgiving of chloride in the water, at the highest cost; ferritic Type 439 and Type 444 resist the same condensate with a lower thermal expansion that suits a welded coil, and they are the materials most condensing coils are drawn from; duplex stainless adds strength and chloride resistance for a high-pressure or aggressive-water service; aluminum-silicon castings condense well and transfer heat readily but corrode outside a narrow water pH band and in contact with copper-bearing system water; cast iron, carbon steel, and copper serve non-condensing duty only, where no condensate ever reaches them, and each has decades of service history in that duty. (9.2.2)
9.2.3 Where the datasheet selects a condensing boiler, the heating surface in contact with flue gas shall be a material the boiler manufacturer lists and warrants for condensing duty.
9.2.4 Where an aluminum alloy heat exchanger is furnished, the Contractor shall furnish the manufacturer's water chemistry limits, including the pH range and the inhibitor compatibility, to the treatment program under HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment before the system is filled.
9.2.5 Where a copper or aluminum heat exchanger is furnished, dielectric isolation shall be provided wherever the boiler connection meets ferrous system piping.

9.3 Pressure Vessel Construction and Jacket

9.3.1 The pressure vessel shall be constructed of the material, thickness, and joint design the Section IV design calculations for the maximum allowable working pressure require, and the welding procedures and welders shall be qualified as Section IV requires.
9.3.2 Each vessel shall be hydrostatically tested at the factory at the pressure Section IV requires for the maximum allowable working pressure, and the test certificate shall be furnished in the closeout submittals.
9.3.3 The boiler jacket shall be factory-insulated and finished, and the factory insulation shall be complete as furnished.
9.3.4 Field insulation of the boiler jacket shall not be accepted in place of factory insulation; insulation of the breeching and the connected piping is the subject of Mechanical InsulationMechanical InsulationResolves to the current adopted revision.sync/mechanical-insulation.
9.3.5 Access openings for cleaning the fireside and the waterside of the heat exchanger shall be provided, sized and located so that every heating surface can be inspected and cleaned without removing the burner or disconnecting the piping, and the vessel shall be furnished with the inspection openings Section IV requires for its size.
NOTE A heat exchanger that cannot be inspected is one whose condition is unknown until it fails, and the cleaning openings are the only means an operator has to see scale on the waterside or soot on the fireside before either becomes a loss of efficiency or a tube failure. (9.3.6)

9.4 Water Flow Through the Boiler

9.4.1 The flow arrangement through each hot water boiler shall be as indicated in the datasheet.
Boiler Flow Arrangementselect
Primary-secondary with a dedicated boiler circulator and hydraulic separation
Variable primary flow with minimum-flow protection
Direct single loop at system flow
NOTE Primary-secondary piping gives each boiler its own circulator and a hydraulic separator, so the boiler sees a constant flow regardless of what the distribution system does, at the cost of a pump per boiler and a mixing penalty that raises the return temperature a condensing boiler sees; variable primary flow drives the system flow through the boilers directly, saves the boiler pumps and the mixing penalty, and depends on a minimum-flow bypass or a controlled minimum pump speed to keep the boiler above its published minimum flow; a direct single loop passes the whole system flow through the boiler with no separation at all, which suits only a boiler whose manufacturer publishes no minimum flow and rates the heat exchanger for the full range the system will produce. (9.4.2)
9.4.3 Where the datasheet selects a direct single loop, the boiler furnished shall be a type for which the manufacturer publishes no minimum flow rate and warrants operation across the full system flow range.
9.4.4 Each boiler shall be protected against flow below the manufacturer's published minimum by a flow-proving switch, a differential pressure switch, or a temperature-rise limit that interrupts the burner, as the boiler listing provides.
9.4.5 The boiler circulator shall be furnished as indicated in the datasheet.
Boiler Circulatorselect
Factory-mounted on the boiler by the boiler manufacturer
Shipped loose by the boiler manufacturer for field installation
Furnished separately as a system pump
None because the boiler operates in a direct single loop
NOTE A factory-mounted circulator is matched to the boiler's pressure drop, wired to its controller, and covered by its warranty, at the cost of a fixed selection; a circulator shipped loose keeps the match and the warranty while letting the installer place it where the piping needs it; a separately furnished pump is selected under HVAC PumpsHVAC PumpsResolves to the current adopted revision.sync/hvac-pumps against the real piping and can be a system-grade pump, but the boiler manufacturer's minimum flow and pump interlock requirements then become the Contractor's coordination items. (9.4.6)
9.4.7 Where the circulator is furnished separately, the pump shall be selected under HVAC PumpsHVAC PumpsResolves to the current adopted revision.sync/hvac-pumps for the scheduled boiler flow at the boiler pressure drop, and the boiler controller shall prove pump operation before the burner is enabled.
9.4.8 The return water temperature protection for a non-condensing boiler shall be as indicated in the datasheet.
Return Water Temperature Protectionselect
Boiler-mounted bypass with a thermostatic valve
Three-way mixing valve controlled on boiler inlet temperature
Variable-speed boiler circulator controlled on boiler inlet temperature
Control sequence that holds the system return above the minimum
Not applicable to a condensing boiler
NOTE A boiler-mounted bypass with a thermostatic valve is self-acting and needs no controls, and it recirculates boiler outlet water back to the inlet so the boiler always sees warm water; a three-way mixing valve does the same under control and can be tuned to the actual loop; a variable-speed circulator raises the inlet temperature by slowing the flow through the boiler, which also raises the temperature rise across it; and a control sequence that holds the system return above the minimum relies on the distribution system cooperating and is the least robust of the four, because a cold-start of a large system can outrun any sequence. (9.4.9)
9.4.10 Where the datasheet selects a non-condensing boiler, the return water temperature at the boiler inlet shall be held at or above the boiler manufacturer's published minimum under every operating condition, including cold start and recovery from setback.

10 Burner and Fuel Train

10.1 Burner Configuration and Firing Control

10.1.1 The burner configuration shall be as indicated in the datasheet.
Burner Configurationselect
Forced-draft power burner
Premix fan-assisted burner
Atmospheric burner with draft hood
Induced-draft burner
Not applicable to an electric boiler
NOTE A forced-draft power burner pushes combustion air through the furnace and delivers a positive furnace pressure, which lets a fire-tube or water-tube boiler be large and tightly packaged; a premix fan-assisted burner mixes gas and air ahead of a surface or mesh burner head, which is the form of most condensing boilers and reaches the lowest NOx without flue gas recirculation; an atmospheric burner draws its air by natural draft through a draft hood and is the simplest and lowest-cost form, limited to Category I venting and to small non-condensing inputs; and an induced-draft burner pulls air through the furnace with a fan at the flue outlet, which keeps the furnace under negative pressure and suits a sectional boiler converted to fan-assisted operation. (10.1.2)
10.1.3 The burner firing control shall be as indicated in the datasheet.
Burner Firing Controlselect
On-off
Two-stage
Multi-stage
Full modulation
NOTE On-off firing is the simplest control and the only choice an atmospheric burner offers, with every cycle costing a purge and a cold start; two-stage and multi-stage firing give a small number of discrete rates and let a plant of several boilers approximate modulation by staging; and full modulation varies the firing rate continuously across the turndown, follows the load without cycling, and is the only firing control that reaches the turndown and the condensing hours a deep-turndown plant is designed for. (10.1.4)
10.1.5 The burner firing control furnished shall be capable of the minimum turndown indicated in the datasheet.
10.1.6 The burner shall be factory-mounted on the boiler, aligned to the furnace, and fire-tested with the boiler before shipment where the factory test indicated in this standard requires it.

10.2 Ignition and Flame Detection

10.2.1 The ignition method shall be as indicated in the datasheet.
Ignition Methodselect
Direct spark ignition
Hot surface ignition
Interrupted pilot
Intermittent pilot
Standing pilot
Manufacturer's standard (by default)
NOTE Direct spark lights the main burner directly and is the standard on premix burners; hot surface ignition lights it from a glowing element with no spark noise and a wear life the element sets; an interrupted pilot lights the main flame and then goes out, so that the flame detector proves the main flame alone, which the codes require on larger inputs; an intermittent pilot stays lit while the main burner fires and goes out between cycles; and a standing pilot burns continuously, wastes fuel, and is permitted only where the boiler listing and the energy code allow it. (10.2.2)
10.2.3 The flame detection method shall be as indicated in the datasheet.
Flame Detection Methodselect
Flame rectification rod
Ultraviolet scanner
Infrared scanner
Self-checking ultraviolet scanner
Manufacturer's standard (by default)
NOTE A flame rectification rod proves a gas flame through the current the flame conducts, is the lowest-cost detector, and cannot see an oil flame; an ultraviolet scanner sees gas and oil flames and is the standard on power burners, with a tube that ages and must be replaced on a schedule; an infrared scanner sees an oil flame through smoke that blinds an ultraviolet scanner and can be fooled by hot refractory; and a self-checking ultraviolet scanner shutters itself to prove it is not reporting a flame that is not there, which NFPA 85 and most insurers require on a burner that fires continuously. (10.2.4)
10.2.5 The pilot and main flame shall each be proved by the flame detector before the fuel safety shutoff valves are permitted to remain open, and the detector shall respond to loss of flame within the time the governing controls code permits.

10.3 Gas Train

10.3.1 The gas train shall begin at the appliance shutoff valve and connector furnished under Fuel Gas PipingFacility Liquefied-Petroleum and Fuel Gas PipingResolves to the current adopted revision.sync/fuel-gas-piping and Natural Gas PipingNatural Gas PipingResolves to the current adopted revision.sync/natural-gas-piping and shall include every device between that valve and the burner.
10.3.2 The gas train shall include a sediment trap, a union or flanged joint that permits the burner to be disconnected without cutting the gas piping, and an inlet pressure test port, downstream of the appliance shutoff valve and upstream of the first train component.
10.3.3 The gas train shall include a pressure regulator with its vent piped to outdoors or of a vent-limiting type listed for indoor installation, the safety shutoff valves, the valve-proving or leak-test provision, and the high and low gas pressure switches that the controls code indicated in the datasheet requires for the boiler input.
10.3.4 The insurer requirements the gas train shall satisfy shall be as indicated in the datasheet.
Fuel Train Insurer Requirementsselect
None beyond the governing controls code
FM Global
IRI
NOTE A train built to the governing controls code alone is what the listing and the jurisdiction require; an FM Global train adds the second safety shutoff valve with proof of closure, the vent valve, and the switch arrangement of Data Sheet 6-4 at inputs where the code does not yet require them, and a property insurer that writes to that standard will not accept less; an IRI train follows the parallel requirements of the former Industrial Risk Insurers, now carried by their successor, and is specified where that insurer or the Owner's corporate standard calls for it. (10.3.5)
10.3.6 The gas inlet pressure the train requires at the appliance shutoff valve shall be as indicated in the datasheet.
Required Gas Inlet Pressure at the Trainrange
in. w.c.
3.54571014285684140
Per drawings — the mechanical equipment schedule and the fuel gas piping drawings (deferred by default)
10.3.7 The Contractor shall confirm that the gas pressure available at the appliance shutoff valve, with every appliance on the gas system at full input, lies within the inlet pressure range the train is built for, and shall report any shortfall or excess before the boiler is ordered.
10.3.8 Where the available pressure exceeds the train's maximum inlet pressure, a line pressure regulator shall be furnished under Fuel Gas PipingFacility Liquefied-Petroleum and Fuel Gas PipingResolves to the current adopted revision.sync/fuel-gas-piping or Natural Gas PipingNatural Gas PipingResolves to the current adopted revision.sync/natural-gas-piping upstream of the appliance shutoff valve, and the boiler shall not be fired until it is installed.
NOTE A gas service that cannot hold the required pressure at full fire is the most common reason a new boiler plant fails its startup, and the failure shows up only when every boiler reaches high fire at once, which is why the confirmation is required against the whole gas system at full input rather than against one boiler alone. (10.3.9)

10.4 Oil Burner Supply

10.4.1 The oil supply arrangement at the burner shall be as indicated in the datasheet.
Oil Supply Arrangement at the Burnerselect
Burner-mounted fuel unit on a single-pipe gravity supply
Burner-mounted fuel unit on a two-pipe supply and return
Pressurized loop from a transfer pump set with a regulator at the burner
Not applicable to the selected heat source
NOTE A single-pipe gravity supply suits a tank above the burner and the smallest inputs, and it cannot purge air from the line by itself; a two-pipe supply and return lets the burner fuel unit lift oil from a tank below the burner and returns the excess, which is the common arrangement for a day tank or a basement tank; and a pressurized loop from a transfer pump set serves several burners from a remote tank, holds the burner inlet at a regulated pressure, and is the arrangement a fuel oil system under Fuel Oil SystemsFacility Fuel-Oil SystemsResolves to the current adopted revision.sync/fuel-oil-systems delivers. (10.4.2)
10.4.3 The oil burner shall be furnished with a fuel unit, a strainer, an oil pressure gauge, and the oil safety shutoff valves the controls code indicated in the datasheet requires for the boiler input.
10.4.4 The burner's required supply pressure, maximum return pressure, and firing-rate flow at the burner connections shall be stated in the submittal and furnished to the fuel oil work under Fuel Oil SystemsFacility Fuel-Oil SystemsResolves to the current adopted revision.sync/fuel-oil-systems.
10.4.5 Where the oil tank is above the burner inlet, an oil safety valve or anti-siphon device shall be installed at the burner as NFPA 31 requires.

10.5 Dual-Fuel Changeover

10.5.1 The fuel changeover for a dual-fuel burner shall be as indicated in the datasheet.
Dual-Fuel Changeoverradio
○ Manual changeover by a selector switch at the boiler
○ Automatic changeover on loss of the primary fuel
10.5.2 Where a dual-fuel burner is furnished, the burner management control shall purge, prove flame, and establish combustion on the second fuel as a new light-off, and shall not transfer fuels with the burner firing unless the burner is listed for on-line transfer.
10.5.3 Where the second fuel is oil, the burner shall be fired on oil at each startup and at each annual service long enough to demonstrate stable combustion at high fire and at the lowest stable firing rate, and the readings shall be recorded.

10.6 Emissions

NOTE Oxides of nitrogen limits for boilers are set by the air district having jurisdiction over the site and vary from no limit at all to single-digit parts per million in a severe non-attainment area; the limit is a permit condition that attaches to the boiler at its rated input, not a property of the boiler class, so the project supplies the limit and the manufacturer supplies the burner that meets it. (10.6.1)
10.6.2 The NOx emission limit each fuel-fired boiler shall meet shall be as indicated in the datasheet.
NOx Emission Limitrange
ppm at 3% oxygen
0150
Derived — the limit the air district having jurisdiction imposes on a boiler of the rated input and heat source at the site, or the absence of one (by default)
NOTE A limit of 0 in the datasheet records that the air district imposes no NOx limit on the boiler. (10.6.3)
10.6.4 The burner furnished shall meet the NOx limit indicated in the datasheet across the full firing range at the project elevation, by whatever combustion technology the manufacturer selects, and the published emission rating shall be stated in the submittal.
NOTE Low-NOx burners reach their ratings by flue gas recirculation, by staged combustion, or by a premix surface burner, and each has a price: flue gas recirculation raises fan power and narrows turndown, staged combustion lowers flame temperature and raises excess air, and a premix surface burner is sensitive to altitude and to the gas composition it was tuned for, so a burner selected for a tight limit at sea level is not assured of the same reading at the site. (10.6.5)
10.6.6 Where the air district requires a source test of the installed boiler, the Contractor shall arrange and bear the cost of the test, and shall correct any exceedance at no cost to the Owner.
10.6.7 Carbon monoxide at the flue shall not exceed the limit the boiler listing permits at any firing rate, and the startup report shall record the reading at each rate tested.

11 Electric Boilers

11.1 Requirements in this section apply where the datasheet selects an electric resistance or electric electrode heat source.
11.2 The electric boiler capacity control shall be as indicated in the datasheet.
Electric Boiler Capacity Controlselect
Single step
Multiple steps staged by contactor
Modulating by silicon-controlled rectifier
Modulating by electrode immersion or shield position
Not applicable to the selected heat source
NOTE A single step gives the simplest control and cycles the full load on and off, which the electrical service sees as a step load; multiple contactor steps let the boiler follow the load in increments and spread wear across the elements; a silicon-controlled rectifier modulates the elements continuously with no contactor wear, at a higher first cost and with harmonic current the electrical design must account for; and an electrode boiler modulates by changing how much of the electrode is immersed or shielded, which gives wide turndown on a very large unit with no elements to replace. (11.3)
11.4 The heating elements of a resistance boiler shall be replaceable through flanged openings without draining the vessel below the element level or disconnecting the piping.
11.5 A resistance boiler shall be furnished with the element step sequencing that limits inrush to the value the electrical service is designed for, and the sequencing shall rotate the lead step so that no element carries the base load alone.
11.6 An electrode boiler shall be furnished with the water conductivity control, the electrode shield or immersion mechanism, and the current-limiting protection its listing requires, and the Contractor shall furnish the conductivity range the boiler requires to the treatment program under HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment before the system is filled.
11.7 Electric boilers shall be installed in accordance with NFPA 70 Article 424 for fixed electric space-heating equipment, including the overcurrent protection, disconnecting means, and control and limit provisions for resistance-type and electrode-type boilers.
11.8 An electric boiler shall be furnished with the operating control, high-temperature limit, low-water cutoff, and relief valve required by Section IV and by the controls code indicated in the datasheet, in the same manner as a fuel-fired boiler.

12 Combustion Air and Venting

12.1 Combustion Air Supply

12.1.1 The combustion air supply shall be as indicated in the datasheet.
Combustion Air Supplyselect
Room air through openings sized per NFPA 54
Room air through a dedicated outdoor air duct to the room
Sealed combustion through separate air and vent pipes
Sealed combustion through a concentric air and vent assembly
Engineered mechanical combustion air interlocked with the burner
Not applicable to an electric boiler
NOTE Room air through louvered openings is the lowest-cost supply and makes the whole boiler room part of the combustion system, so it is exposed to every exhaust fan in the building and to the dust and vapors of whatever shares the room; a dedicated outdoor air duct to the room keeps the room arrangement but gives it its own source; sealed combustion pipes outdoor air directly to the burner, which is the standard on condensing boilers, isolates combustion from room pressure and room contaminants, and is limited by the equivalent length the boiler manufacturer allows; a concentric assembly carries the air and vent in one wall or roof penetration; and an engineered mechanical system supplies a large plant through a fan and dampers interlocked to the burners, which is the only practical supply for a plant whose input exceeds what gravity openings can serve. (12.1.2)
12.1.3 Combustion air openings, ducts, and pipes shall be sized in accordance with NFPA 54 or the adopted fuel gas code, and in accordance with NFPA 31 for an oil-fired boiler.
12.1.4 Where the datasheet selects room air, the Contractor shall verify before startup that the boiler room does not go negative with respect to outdoors under the worst combination of exhaust the building can operate, and shall report a negative result before the boiler is fired.
12.1.5 Where the datasheet selects an engineered mechanical combustion air system, the burner shall be interlocked to prove combustion air flow before it fires and to shut down on loss of flow.
12.1.6 Where the datasheet selects sealed combustion, the air intake pipe shall be the material and size the boiler manufacturer names, and its equivalent length shall not exceed the manufacturer's published maximum for the vent length actually installed.
12.1.7 Combustion air shall not be drawn from a space containing halogenated solvents, chlorinated compounds, or treatment chemicals stored open, because the combustion products of those vapors are acids that attack the heat exchanger and the vent.

12.2 Vent Category and Material

NOTE A gas-fired boiler is classified by two independent facts: whether its vent runs above or below atmospheric pressure, and whether the flue gas condenses in the vent; the category sets what the vent must be made of and how it must be joined, and a vent built for the wrong category leaks flue gas or condensate into the building. (12.2.1)
12.2.2 The vent category of each gas-fired boiler shall be as indicated in the datasheet.
Vent Categoryselect
Category I
Category II
Category III
Category IV
Not applicable to an oil-fired or electric boiler
Derived — the burner configuration and combustion technology of the boiler furnished, as classified under ANSI Z21.13 and NFPA 54 (by default)
NOTE Category I is negative pressure and non-condensing, Category II is negative pressure and condensing, Category III is positive pressure and non-condensing, and Category IV is positive pressure and condensing. (12.2.3)
12.2.4 The vent material shall be as indicated in the datasheet.
Vent Materialselect
Type B double-wall gas vent listed to UL 441
Type L vent listed to UL 641
Factory-built chimney listed to UL 103
AL29-4C stainless steel special gas vent listed to UL 1738
Type 316L stainless steel special gas vent listed to UL 1738
Polypropylene special gas vent listed to UL 1738
PVC
CPVC
Field-fabricated welded steel breeching and stack
Not applicable to an electric boiler
NOTE Type B vent serves Category I gas appliances only and is the lowest-cost listed vent; Type L vent serves oil-fired and Category I gas appliances at the higher flue temperatures oil produces; a factory-built chimney serves any fuel at the highest flue temperatures and is the listed form for an oil-fired or a large non-condensing boiler; AL29-4C stainless is the special gas vent for Category II, III, and IV service with the widest temperature margin and the longest service record on positive-pressure condensing flues; Type 316L stainless serves the same categories at a lower cost with less resistance to the chlorides in condensate; polypropylene serves Category II and IV condensing boilers within its temperature rating at the lowest cost of the listed condensing vents; PVC and CPVC are the lowest-cost condensing vent materials, permitted only where the boiler listing names them and the jurisdiction accepts them, with CPVC carrying the higher temperature rating; and a field-fabricated welded steel breeching and stack is the engineered form for a large plant whose flue a listed vent cannot serve, designed under NFPA 211 and lined or made of stainless where condensate can form. (12.2.5)
12.2.6 The vent material shall be listed for the vent category of the boiler and shall be a material the boiler manufacturer names in the installation instructions for the specific model furnished.
12.2.7 An oil-fired boiler shall be vented through a Type L vent, a factory-built chimney, a masonry chimney with a listed liner, or a field-fabricated breeching and stack, as NFPA 31 and the boiler listing permit.
12.2.8 Unless the datasheet selects PVC or CPVC, plastic pipe not listed to UL 1738 shall not be used to vent a boiler under this standard.
12.2.9 Where the datasheet selects PVC or CPVC, the Contractor shall obtain written confirmation from the Authority Having Jurisdiction that the material is accepted for the boiler before the vent is fabricated.
NOTE Some jurisdictions restrict plastic venting of gas-fired condensing boilers on the grounds of long-term durability and of flue gas temperature during an abnormal firing condition, and the stainless and polypropylene materials do not carry that exposure. (12.2.10)
12.2.11 A positive-pressure vent shall be gas-tight by construction, joined and sealed as its listing requires, and shall not depend on draft to keep flue gas out of the building.
12.2.12 A vent serving a condensing boiler shall be pitched back toward the boiler or toward a condensate drain at the slope the vent listing requires, with every joint made to carry condensate without leaking.

12.3 Vent Arrangement and Draft Control

12.3.1 The vent arrangement shall be as indicated in the datasheet.
Vent Arrangementselect
One vent serving one boiler
A common vent serving multiple boilers of the same model
A common breeching with an engineered draft control system
A breeching into an existing masonry chimney with a listed liner
Not applicable to an electric boiler
NOTE One vent per boiler is the simplest arrangement, is the only one most condensing boiler listings permit without an engineered system, and multiplies penetrations; a common vent for boilers of the same model is permitted by some manufacturers with their own sizing method and a backflow preventer at each boiler, and it saves penetrations at the cost of a vent that must work with any combination of boilers firing; a common breeching with an engineered draft control serves a plant of large boilers through one stack with a draft inducer and sequencing dampers that hold the draft at each boiler outlet; and a breeching into an existing masonry chimney reuses a chimney that must be lined to the category of the new boilers, which a non-condensing boiler with a listed liner can use and a condensing boiler usually cannot. (12.3.2)
12.3.3 Common vents shall be sized by the NFPA 54 vent tables or by an engineered method the vent or boiler manufacturer publishes for the configuration.
12.3.4 Boilers from different manufacturers shall not share a positive-pressure vent unless each manufacturer confirms the proposed configuration in writing.
12.3.5 Where boilers share a vent, each boiler shall be furnished with a vent backflow preventer or a motorized vent damper interlocked with its burner, as the boiler listing requires, so that flue gas from a firing boiler cannot pass through an idle one.
12.3.6 The draft control shall be as indicated in the datasheet.
Draft Controlselect
None because the boiler controls its own vent pressure
Barometric draft regulator
Motorized vent damper interlocked with the burner
Mechanical draft inducer with a proving switch
Sequencing draft control with modulating dampers at each boiler
Not applicable to an electric boiler
NOTE A boiler with a fan-assisted or premix burner controls its own vent pressure and needs no external draft control; a barometric draft regulator admits room air to hold a stable negative draft on a natural-draft or oil-fired boiler through changes in wind and stack temperature, at the cost of dilution air up the stack; a motorized vent damper closes an idle boiler off from the stack to stop standby losses and is required by the energy code on some natural-draft boilers; a mechanical draft inducer pulls the flue gas through a vent that cannot develop enough natural draft and is interlocked so the burner cannot fire without it; and a sequencing draft control holds the draft at each boiler outlet of a common breeching as boilers start and stop, which is the only way a large multiple-boiler plant on one stack keeps every boiler within its draft range. (12.3.7)
12.3.8 Draft inducers, exhausters, and power venters shall be listed to UL 378 and shall be interlocked to prove operation before the burner fires and to shut the burner down on loss of draft.
12.3.9 Where a draft control is furnished, the draft at each boiler flue outlet shall be measured at startup at high fire and at low fire, with every other boiler on the stack both firing and off, and shall be within the boiler manufacturer's published range at every condition.

12.4 Breeching and Termination

12.4.1 Field-fabricated breeching and stack shall be designed for the vent category, the flue gas temperature, and the vent pressure of the boilers served, in accordance with NFPA 211 and the adopted mechanical code, and shall be constructed of welded carbon steel or stainless steel with the thickness the design requires.
12.4.2 Breeching serving a condensing boiler, or any breeching in which condensate can form at low fire, shall be constructed of stainless steel or lined with a material resistant to flue gas condensate, and shall be drained at every low point.
12.4.3 Breeching shall be supported independently of the boiler, with expansion joints or flexible connectors where thermal growth would load a boiler flue collar.
12.4.4 Breeching shall be provided with cleanout openings at each change of direction and at the base of each vertical stack, and with a test port for combustion analysis at each boiler flue outlet.
12.4.5 Vent and combustion air terminations shall be located as shown on the roof plan and exterior elevations.
12.4.6 The Contractor shall verify that each termination clears building openings, air intakes, adjacent terminations, walking surfaces, grade, property lines, and the local snow accumulation depth by the distances the boiler manufacturer and the adopted fuel gas code require, and shall report any conflict before the vent is fabricated.
NOTE A condensing boiler's flue plume is wet, and in cold weather it freezes on whatever it drifts across; a termination placed under a soffit, beside a walkway, or upwind of an air intake becomes an ice and odor complaint the first winter, which is why the clearances are verified against the real roof rather than taken from the vent listing alone. (12.4.7)
NOTE Insulation of breeching and stack is the subject of Mechanical InsulationMechanical InsulationResolves to the current adopted revision.sync/mechanical-insulation. (12.4.8)

12.5 Flue Gas Condensate

NOTE Flue gas condensate from a condensing boiler is acidic enough to attack cast iron, galvanized steel, copper, and concrete, so it is neutralized before it enters a drainage system built from those materials. (12.5.1)
12.5.2 Condensate handling shall be as indicated in the datasheet.
Flue Gas Condensate Handlingselect
Neutralizer draining by gravity to an indirect waste receptor
Neutralizer draining by gravity to a floor drain
Neutralizer discharging through a condensate pump to an indirect waste receptor
Direct discharge to an acid-resistant drainage system without neutralization
Not applicable to a non-condensing or electric boiler
NOTE Gravity drainage to a receptor is the simplest handling and needs a receptor below the boiler's drain outlet; a floor drain serves the same way where the drain body and the piping below it are acid-resistant; a condensate pump lifts the condensate where no receptor is low enough and adds a pump that can fail and flood the boiler; and direct discharge without neutralization is accepted only where the whole drainage path to the building drain is built of acid-resistant material and the sewer authority accepts the discharge. (12.5.3)
12.5.4 Unless the datasheet selects direct discharge to an acid-resistant drainage system, condensate from each condensing boiler shall pass through a neutralizer before it reaches the drainage system.
12.5.5 The neutralizer shall be furnished with replaceable media, sized for the condensate rate of the boiler at full input, and installed so the media can be changed without cutting piping.
12.5.6 Condensate piping shall be PVC, CPVC, polypropylene, or stainless steel, and shall not be copper, brass, galvanized steel, or bare carbon steel.
12.5.7 Condensate piping shall be trapped as the boiler manufacturer requires and routed to fall continuously to the receptor.
12.5.8 Any condensate pump furnished shall alarm on high level to the building automation interface specified in this standard and shall interrupt the burner on high level where the boiler listing requires it.
12.5.9 Condensate discharge shall terminate over the receptors shown on the mechanical plans.

13 Boiler Trim and Safety Devices

13.1 Relief and Safety Valves

13.1.1 Each hot water boiler shall be furnished with a pressure relief valve, and each steam boiler with a safety valve, certified to ASME BPVC Section IV and bearing the ASME Certification Mark with the HV designator.
13.1.2 The relief valve set pressure shall be as indicated in the datasheet.
Relief Valve Set Pressurerange
psig
101530404550607580100125150160
Derived — the maximum allowable working pressure of the boiler furnished and the heating medium (by default)
13.1.3 The relief valve set pressure shall not exceed the maximum allowable working pressure of the boiler, and the relieving capacity shall equal or exceed the gross output of the boiler.
13.1.4 The relief valve shall be installed in the connection the boiler manufacturer designates for it, in the vertical position, with no valve, restriction, or reduction in size between the boiler and the valve inlet.
13.1.5 Relief valve discharge piping shall be the full size of the valve outlet over its entire length, shall fall continuously from the valve, shall terminate through an air gap over a receptor placed where a discharge is visible to operating staff and cannot reach a person, and shall not be trapped, valved, or threaded at its outlet end.
13.1.6 Where several boilers discharge to a common relief header, the header shall be sized for the simultaneous discharge of every valve connected to it, and no isolation valve shall be installed in it.
NOTE The relief valve on a loop that an isolation valve can separate from the boiler is furnished under Hydronic SpecialtiesHydronic SpecialtiesResolves to the current adopted revision.sync/hydronic-specialties; the valve on the boiler itself is furnished with the boiler under this standard, and the two set pressures are coordinated so that the loop valve never carries the boiler's duty. (13.1.7)

13.2 Low-Water Cutoff

NOTE Firing a boiler whose heating surface has lost its water is the most destructive thing that can happen to it: the metal overheats, distorts, and can rupture, and on a steam boiler the water that follows a dry-fire can flash and fail the vessel. The low-water cutoff is the device that stops it, and it is the one device on the boiler that is tested at every service. (13.2.1)
13.2.2 Each boiler shall be furnished with a low-water cutoff that interrupts the burner before the water falls below the lowest safe level the boiler manufacturer establishes.
13.2.3 Each steam boiler shall be furnished with two independent low-water cutoffs, the lower of which shall require manual reset.
13.2.4 Each hot water boiler shall be furnished with at least one low-water cutoff installed in the boiler or in the supply piping at the elevation the boiler manufacturer and the controls code require.
13.2.5 The low-water cutoff sensing type shall be as indicated in the datasheet.
Low-Water Cutoff Sensing Typeselect
Conductivity probe
Float with mechanical switch
Float with magnetic switch
Manufacturer's standard (by default)
NOTE A conductivity probe has no moving parts, fits a hot water boiler with no water column, and depends on the water's conductivity, which treated or glycol-charged water can carry outside the probe's range; a float with a mechanical switch is the traditional steam boiler device, is testable by blowdown, and accumulates sludge in its chamber; and a float with a magnetic switch keeps the float but seals the switch from the water, which suits a boiler whose chamber cannot be blown down on a schedule. (13.2.6)
13.2.7 The reset type of the hot water boiler low-water cutoff shall be as indicated in the datasheet.
Hot Water Low-Water Cutoff Resetradio
○ Automatic reset
○ Manual reset
NOTE An automatic reset restarts the boiler when the water returns and lets a plant recover from a transient air pocket without an operator, and it also lets a boiler cycle on a slow leak until the leak finds it; a manual reset keeps the boiler off until someone has looked at why the water fell, which many jurisdictions and most boiler insurers require, and which a plant without a resident operator has to weigh against the heating outage that follows a nuisance trip. (13.2.8)
13.2.9 Each low-water cutoff shall be provided with a means of testing it under operating conditions, by blowdown on a float type or by a test switch on a probe type, without draining the boiler.
13.2.10 Each float-type low-water cutoff shall be installed with a blowdown valve piped to the receptor, so the chamber can be flushed on the schedule the manufacturer requires.

13.3 Operating and Limit Controls

13.3.1 Each boiler shall be furnished with an operating control that cycles or modulates the burner to hold the supply temperature or steam pressure setpoint.
13.3.2 Each boiler shall be furnished with a high-limit control, independent of the operating control and sensing the same medium through its own sensor, that interrupts the burner when the supply temperature or steam pressure exceeds the limit setpoint.
13.3.3 The high-limit control shall require manual reset.
13.3.4 A hot water boiler shall be furnished with a temperature high limit and a steam boiler with a pressure high limit, each set at or below the value the boiler listing and the controls code indicated in the datasheet permit for the maximum allowable working pressure and rated temperature.
13.3.5 Each boiler shall be furnished with the flow-proving, combustion air proving, high and low fuel pressure, and vent or draft proving interlocks that the controls code indicated in the datasheet requires for the boiler input and the fuel, each wired into the burner management limit circuit.
NOTE The operating control and the high limit are two devices because the operating control is the one that fails most, by sensor drift or by a stuck relay, and the limit exists only to catch that failure; a single device doing both jobs protects the boiler against nothing but itself. (13.3.6)
13.3.7 The factory-furnished control and safety package shall not be modified, bypassed, jumpered, or defeated.
13.3.8 Any field-furnished control shall be external to the boiler control and shall not override a safety function.

13.4 Gauges and Trim

13.4.1 Each hot water boiler shall be furnished with a combination temperature and pressure gauge reading the boiler outlet, a drain valve at the lowest point of the vessel, and an air vent connection at the highest point.
13.4.2 Each steam boiler shall be furnished with a steam pressure gauge with a siphon and a gauge cock, a water gauge glass with try-cocks or a listed equivalent, and a bottom blowdown valve.
13.4.3 Gauges shall be positioned so they can be read from the front of the boiler without removing a cover or a shield, with a dial range of about twice the operating value.
13.4.4 The additional trim and accessories furnished with each boiler shall be as indicated in the datasheet.
Additional Boiler Trim and Accessoriescheckbox
☐ Supply and return thermowells with thermometers
☐ Stack thermometer at the flue outlet
☐ Fuel flow meter
☐ Run-time hour meter
☐ Boiler isolation valve set furnished with the boiler
☐ Surface blowdown connection and valve
☐ Factory-mounted condensate neutralizer
☐ Stack flue gas sampling port
NOTE Supply and return thermometers let an operator see the temperature rise across the boiler without an instrument; a stack thermometer is the earliest sign of a fouled heat exchanger, because the stack temperature climbs as the heating surface stops transferring heat; a fuel flow meter and a run-time meter turn the boiler into something that can be measured against its rating; a factory-furnished isolation valve set is matched to the connections and shipped with the boiler; a surface blowdown connection lets a steam boiler skim the solids that concentrate at the water line; a factory-mounted neutralizer saves a field assembly on a small condensing boiler; and a flue gas sampling port is what every combustion test depends on. (13.4.5)
13.4.6 All trim shall be factory-mounted and piped to the extent the boiler manufacturer's shipping arrangement permits, so that field connections are limited to the piping, fuel, vent, drain, and electrical connections.

13.5 Steam Boiler Trim and Feedwater Control

13.5.1 Requirements in this article apply where the datasheet selects low-pressure steam as the heating medium.
13.5.2 The feedwater control arrangement shall be as indicated in the datasheet.
Steam Boiler Feedwater Controlselect
Float-operated pump controller mounted on the boiler
Level transmitter with modulating feedwater valve
Level transmitter with variable-speed feed pump
Not applicable to a hot water boiler
NOTE A float-operated pump controller starts and stops the feed pump on the boiler's own water level, is the traditional device on a low-pressure steam boiler, and feeds in slugs of cold water that the boiler sees as a load swing; a level transmitter with a modulating feedwater valve holds the level continuously from a running feed pump, which suits a boiler whose steam load changes fast; and a level transmitter with a variable-speed feed pump does the same without the valve, at the cost of a drive the pump work must furnish. (13.5.3)
13.5.4 Each steam boiler shall be furnished with a water column or an equivalent level chamber carrying the gauge glass, the low-water cutoffs, and the pump controller where one is furnished, connected to the boiler so that the chamber can be blown down to the receptor.
13.5.5 Each steam boiler shall be furnished with a feedwater connection, a check valve and a stop valve on the feedwater line at the boiler, and a feedwater inlet arranged so that cold feedwater does not impinge directly on the heating surface.
NOTE The boiler feed pump or feed unit, the condensate receiver, and the condensate return piping are the subject of Steam And Condensate PipingSteam and Condensate PipingResolves to the current adopted revision.sync/steam-and-condensate-piping and HVAC PumpsHVAC PumpsResolves to the current adopted revision.sync/hvac-pumps; this standard governs the connection on the boiler and the control that calls for feedwater. (13.5.6)
13.5.7 Each steam boiler shall be furnished with a bottom blowdown connection and valve sized as Section IV requires for the boiler, piped to a blowdown receptor or tank that cools the discharge to the temperature the sewer authority permits.
13.5.8 Each steam boiler shall be furnished with a steam outlet stop valve, and with a non-return valve in addition where the boiler is one of several on a common header, as the adopted mechanical code and Section IV require.
NOTE The water treatment of the boiler, including cycles of concentration, the blowdown schedule, and the condensate corrosion program, is the subject of HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment. (13.5.9)

14 Controls and Plant Sequencing

14.1 Burner Management

14.1.1 Each fuel-fired boiler shall be furnished with a burner management control that executes a timed prepurge, a trial for pilot ignition, a trial for main flame ignition, flame supervision throughout firing, and a postpurge, in the sequence and with the timings the controls code indicated in the datasheet requires for the boiler input and fuel.
14.1.2 The burner management control shall lock out the burner on loss of flame, on failure to ignite within the trial period, and on opening of any limit or interlock in the limit circuit, and the lockout shall require manual reset at the boiler.
14.1.3 The burner management control shall display, or report through the building automation interface, the cause of each lockout, and shall retain the record of at least the last ten lockouts through a loss of power.
NOTE The prepurge is the only defense against lighting a furnace that already holds fuel, and it is the step an operator under pressure to restore heat is most tempted to shorten; the sequence is specified so that the control, and not the operator, decides when the furnace is clear. (14.1.4)
14.1.5 The prepurge shall prove combustion air flow and, where the controls code requires it, the low-fire start position of the fuel-air control, before the trial for ignition begins.
14.1.6 Where NFPA 85 governs the boiler, the Contractor shall prepare, submit, and execute the written commissioning plan NFPA 85 requires, and shall not fire the boiler for sustained operation until the plan has been completed and signed.

14.2 Fuel-Air Ratio Control

14.2.1 The fuel-air ratio control shall be as indicated in the datasheet.
Fuel-Air Ratio Controlselect
Single-point mechanical linkage
Parallel positioning without oxygen trim
Parallel positioning with oxygen trim
Premix fan speed with fixed gas-air ratio valve
Not applicable to an electric boiler
NOTE A single-point mechanical linkage moves the fuel valve and the air damper from one actuator through a jackshaft, is the lowest-cost control, and holds the ratio only as well as the linkage holds its adjustment, so it is set rich to be safe and loses efficiency across the range; parallel positioning drives the fuel and air with separate actuators from a curve stored in the controller, holds the curve at every point, and needs no linkage adjustment; oxygen trim adds a flue gas oxygen sensor that corrects the air for changes in fuel composition, temperature, and barometric pressure, which pays back on a large boiler that fires most of the year and adds a sensor to calibrate on a small one that cycles; and a premix burner holds its ratio through a gas valve that follows the fan's air flow, which is the form of most condensing boilers and has no curve to set. (14.2.2)
14.2.3 Where the datasheet selects oxygen trim, the trim control shall be limited so that it cannot drive the air below the minimum the burner management permits, and loss of the oxygen sensor shall return the burner to its base curve rather than lock it out.
14.2.4 The fuel-air ratio at every firing rate tested shall be set at startup so that the flue gas oxygen, carbon monoxide, and stack temperature fall within the boiler manufacturer's published range, and the as-left values shall be recorded.

14.3 Plant Sequencing and Supply Temperature Reset

14.3.1 The controller that stages the boilers shall be as indicated in the datasheet.
Plant Sequencing Controllerselect
Boiler manufacturer's cascade controller mounted on the lead boiler
Standalone lead-lag controller furnished with the boilers
Building automation system sequencing
None because the plant has a single boiler
NOTE The boiler manufacturer's cascade controller stages boilers of the same model from the lead boiler's own control, knows each boiler's turndown and firing state exactly, and reports to the building automation system as a single device; a standalone lead-lag controller does the same for boilers of mixed make or vintage through hardwired firing-rate signals; and building automation system sequencing puts the staging logic where the rest of the plant's logic lives, with full access to the system sensors and the schedule, at the cost of a plant that stops staging when the network does, unless each boiler can fall back to local control. (14.3.2)
14.3.3 The sequencing controller shall stage boilers on and off in response to the plant load, shall rotate the lead boiler on an adjustable schedule, and shall stage so that the running boilers operate at the firing rates that give the plant its highest efficiency rather than at the fewest boilers running.
14.3.4 On loss of the sequencing controller or its network, each boiler shall revert to local control at its own setpoint, and the plant shall continue to deliver heat.
NOTE A condensing plant is most efficient with the most boilers running at the lowest fire, because efficiency rises as firing rate falls, while a non-condensing plant is most efficient with the fewest boilers running near high fire, because standby losses dominate at low fire; the staging rule is therefore written in terms of efficiency rather than in terms of the number of boilers, so that the same sequence is not applied to both. (14.3.5)
14.3.6 The supply temperature reset shall be as indicated in the datasheet.
Supply Temperature Resetselect
Outdoor air reset in the boiler or plant controller
Outdoor air reset from the building automation system
Demand-based reset from the building automation system on terminal valve position
Fixed setpoint
NOTE Outdoor air reset lowers the supply temperature as the outdoor temperature rises on a fixed schedule, needs only an outdoor sensor, and is the reset most energy codes require on a hot water plant above a threshold capacity; placing it in the boiler controller keeps it working without the network, and placing it in the building automation system lets it be tuned with the rest of the plant; demand-based reset lowers the supply temperature until the most-open terminal valve is nearly fully open, which follows the real load rather than a proxy for it and delivers the most condensing hours, at the cost of valve position feedback from every terminal; and a fixed setpoint is the simplest control, never condenses more than the design return allows, and is the right choice only where the energy code permits it and the load does not vary. (14.3.7)
14.3.8 Where Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code requires supply water temperature reset for the plant's design output, the reset furnished shall satisfy that requirement, and the reset schedule shall be recorded in the startup report.
14.3.9 The reset schedule shall not lower the supply temperature below the minimum the terminal equipment, the domestic water heating load, or the non-condensing boiler's return protection requires, and that minimum shall be recorded in the controls configuration.

14.4 Building Automation Interface

14.4.1 The boiler controls shall interface with the building automation system as indicated in the datasheet.
Building Automation Interfaceselect
Hardwired enable, firing-rate signal, status, and alarm contacts only
BACnet MS/TP
BACnet/IP
Modbus RTU
Modbus TCP
LonWorks
NOTE A hardwired interface carries an enable contact, a 0 to 10 V or 4 to 20 mA firing-rate or setpoint signal, and status and alarm contacts, works with any building automation system, and exposes nothing the controller knows beyond those points; BACnet MS/TP puts the full point list on a serial field bus at the lowest cost; BACnet/IP puts it on the building network with the speed and addressing that a plant of many boilers needs; Modbus RTU and Modbus TCP carry the same points to a system that speaks Modbus natively, with register maps that the integrator must map by hand; and LonWorks serves an existing system built on it. (14.4.2)
14.4.3 Each boiler shall accept a remote enable, a remote setpoint or a firing-rate command, and shall report, at minimum, run status, firing rate, supply and return temperature or steam pressure, lockout alarm, and the cause of the last lockout.
14.4.4 The points made available to the building automation system shall be as indicated in the datasheet.
Monitored and Commanded Pointscheckbox
☐ Boiler enable command
☐ Supply temperature or steam pressure setpoint
☐ Firing-rate command
☐ Run status
☐ Firing rate feedback
☐ Supply and return temperature or steam pressure
☐ Lockout alarm with cause
☐ Low-water cutoff alarm
☐ High-limit alarm
☐ Flue gas temperature
☐ Flue gas oxygen
☐ Boiler circulator status
☐ Condensate pump or neutralizer alarm
☐ Sump high level alarm
☐ Fuel consumption
☐ Run-time hours
14.4.5 Network points, addressing, protocol settings, and the point naming convention shall be coordinated with Building Automation SystemBuilding Automation SystemResolves to the current adopted revision.sync/building-automation-system.
14.4.6 Temperature points reported by the boiler shall be sensed by the boiler's own immersion sensors, and any system sensor beyond the boiler connections shall be furnished under HVAC Controls InstrumentationHVAC Instrumentation and Control DevicesResolves to the current adopted revision.sync/hvac-controls-instrumentation.

14.5 Electrical Supply at the Boiler

14.5.1 The supply voltage to each boiler shall be as indicated in the datasheet.
Supply Voltagerange
V
120208240277347480600
Per drawings — the mechanical equipment schedule (deferred by default)
14.5.2 The supply phase shall be as indicated in the datasheet.
Supply Phaseselect
1Φ
3Φ
Per drawings — the mechanical equipment schedule (deferred by default)
14.5.3 The power connection arrangement shall be as indicated in the datasheet.
Power Connectionradio
● Single-point power connection with factory control transformer
○ Separate power and control circuits
14.5.4 Each boiler shall be furnished with a factory-wired control panel that accepts the supply voltage and phase indicated in the datasheet and distributes power to the burner, the circulator where one is factory-mounted, and the controls.
14.5.5 Branch-circuit conductors, overcurrent protection, and the disconnecting means rating shall match the nameplate values of the boiler actually furnished, and the Contractor shall report any difference between those values and the scheduled electrical characteristics before rough-in.
14.5.6 The disconnecting means shall be furnished under Enclosed Switches And DisconnectsEnclosed Switches and DisconnectsResolves to the current adopted revision.sync/enclosed-switches-and-disconnects and located within sight of the boiler.
14.5.7 An emergency shutoff switch that de-energizes the burner of every boiler in the room shall be installed outside each boiler room entrance, labeled, and located as ASME CSD-1 and the adopted mechanical code require.
14.5.8 Equipment grounding and bonding shall comply with Grounding And BondingGrounding and Bonding for Electrical SystemsResolves to the current adopted revision.sync/grounding-and-bonding.

15 Factory Testing

15.1 The factory test of each boiler shall be as indicated in the datasheet.
Factory Testradio
● Hydrostatic test only
○ Hydrostatic test and factory fire test of the boiler and burner assembly
NOTE A hydrostatic test is required by Section IV on every vessel and proves only the pressure boundary; a factory fire test runs the boiler and burner together before shipment, sets the combustion curve under controlled conditions, and catches a mismatched burner or a leaking fuel train before the boiler is in a room where it cannot be returned, at the cost of the test and of a lead time the schedule has to carry. (15.2)
15.3 The hydrostatic test of each pressure vessel shall be performed at the factory in the presence of the Authorized Inspector at the pressure Section IV requires, and the vessel shall show no leakage or permanent deformation.
15.4 Where a factory fire test is indicated, the boiler shall be fired on the fuel the project will use, or on a fuel the manufacturer demonstrates to be equivalent for the test, at high fire and at the minimum turndown indicated in the datasheet, and the combustion readings shall be furnished in the closeout submittals.
15.5 The Owner's representative may witness the factory fire test, and the Contractor shall give at least ten working days' notice of the test date.

16 Installation

16.1 Equipment Setting and Anchorage

16.1.1 The boiler support shall be as indicated in the datasheet.
Boiler Supportselect
A concrete housekeeping pad
The finished floor slab
A structural steel stand or rails
Roof dunnage or a curb for an outdoor boiler
A wall-mounted bracket furnished by the boiler manufacturer
NOTE A housekeeping pad raises the boiler above wash-down water and spilled condensate and gives the anchors something to bite, and it is the norm for a floor-standing boiler; the finished slab serves a light boiler where the slab is the structure the anchors engage; a steel stand or rails lift a boiler to the height its drain or its tube pull needs; roof dunnage or a curb carries an outdoor boiler above the roof membrane; and a wall bracket carries a small wall-hung boiler on the structure the manufacturer's bracket is listed for. (16.1.2)
16.1.3 The housekeeping pad, where one is indicated, shall be furnished under Concrete PadsConcrete Equipment PadsResolves to the current adopted revision.sync/concrete-pads, sized to extend beyond the boiler base on every side by the distance the anchorage design requires.
16.1.4 Each boiler shall be set level, fully bearing on its support, and shimmed only with corrosion-resistant shims where leveling is required.
16.1.5 A boiler shall be rigidly mounted, without vibration isolators, unless the boiler manufacturer requires isolation for the burner or the Engineer of Record indicates it for the installation.
16.1.6 The seismic anchorage shall be as indicated in the datasheet.
Seismic Anchorageselect
None required
A pre-approved anchorage detail listed by an evaluation agency
Project-specific anchorage engineered for the installation
Derived — Seismic Design CategorySeismic Design CategoryParameterEach project supplies its own value.seismic-design-category and the component importance factor the project assigns to the heating plant (by default)
16.1.7 Anchorage shall resist the seismic forces ASCE 7 assigns to the component, and the vent, fuel, and piping connections shall be arranged so that the design displacement does not load them.
16.1.8 Where anchorage is engineered for the project, the anchorage design shall be sealed by a registered design professional licensed in the project's jurisdiction.
16.1.9 Where a pre-approved anchorage detail is used, it shall be a detail listed for the boiler weight, geometry, and mounting condition actually installed.
16.1.10 Anchorage hardware, restraint, and special inspection shall comply with Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current adopted revision.sync/vibration-isolation-and-seismic-restraint.

16.2 Clearances and Service Access

16.2.1 Clearances to combustible construction shall equal or exceed the clearances on the boiler listing label and those the adopted mechanical code requires.
16.2.2 Service clearances shall equal or exceed the boiler manufacturer's published minimums and the working space NFPA 70 requires at the control panel and the disconnecting means.
16.2.3 Clear space equal to the tube length plus the withdrawal allowance the manufacturer publishes shall be maintained at the tube-pull end of every fire-tube and water-tube boiler, and clear space to remove a section shall be maintained beside every sectional boiler.
16.2.4 Each boiler shall be set so that the burner can be swung open or withdrawn, every cleaning opening can be opened, and the largest single component requiring replacement can be removed from the room without dismantling permanent building construction.
NOTE A boiler set against a wall at its listed clearance meets the code and still cannot be serviced, because the listing clearance is a fire clearance and says nothing about a technician's reach or a tube's length; the service clearances here are the ones that decide whether the heat exchanger can be cleaned ten years from now. (16.2.5)

16.3 Piping Connections at the Boiler

16.3.1 The connection type at the boiler supply and return or steam and condensate connections shall be as indicated in the datasheet.
Boiler Connection Typeselect
Threaded
Flanged
Grooved
Manufacturer's standard (by default)
NOTE Threaded connections are the manufacturer's standard on small boilers and are the hardest to break without cutting; flanged connections are the standard on large boilers and let the boiler be removed by unbolting; and grooved connections give the same removability on a boiler whose manufacturer offers grooved nozzles, with a coupling whose gasket must be rated for the boiler's temperature. (16.3.2)
16.3.3 Each boiler water connection shall be provided with an isolation valve, furnished under HVAC Piping ValvesGeneral-Duty Valves for HVAC PipingResolves to the current adopted revision.sync/hvac-piping-valves unless the datasheet includes the isolation valve set with the boiler, and with a union, flange, or grooved coupling between the valve and the boiler so that the boiler can be removed without cutting the system piping.
16.3.4 Isolation valves shall be arranged so that any one boiler can be isolated, drained, and serviced while the rest of the plant continues to operate.
16.3.5 Piping shall be supported independently of the boiler so that no piping weight or thermal movement is carried by a boiler connection.
16.3.6 A dielectric fitting shall be installed wherever a copper, bronze, or aluminum boiler connection meets ferrous system piping.
16.3.7 Each boiler shall be provided with a full-port drain valve at its drain connection, fitted with a hose-thread outlet and a cap, and the Contractor shall confirm before setting the boiler that the drain and the receptor together permit a complete drain-down without flooding the room.
16.3.8 The connections between the boiler and the hydronic system piping, the expansion tank, the air separator, and the system fill shall be made as Hydronic PipingHydronic PipingResolves to the current adopted revision.sync/hydronic-piping and Expansion Tanks And Air SeparatorsExpansion Tanks and Air SeparatorsResolves to the current adopted revision.sync/expansion-tanks-and-air-separators require, and the point of no pressure change shall be located as those standards require relative to the boiler circulator.

16.4 Fuel and Electrical Connections at the Boiler

16.4.1 The fuel gas connection to the train shall be made with rigid pipe from the appliance shutoff valve, or with a listed appliance connector where the boiler listing and the adopted fuel gas code permit one, and the train shall be supported so that no load is carried by the boiler gas valve.
16.4.2 Where a gas pressure regulator in the train has a vent, the vent shall be piped to outdoors at a location where the discharge cannot enter a building opening, or the regulator shall be of a vent-limiting type listed for indoor installation.
16.4.3 The gas train shall be leak-tested at the train's working pressure after connection and before the first firing, and the safety shutoff valves shall be leak-tested by the method the controls code indicated in the datasheet requires.
16.4.4 The oil supply and return connections at the burner shall be made with flexible connectors listed for fuel oil, with isolation valves on both lines at the burner.
16.4.5 The power and control wiring to the boiler shall be run in raceway as Raceways And ConduitRaceways and ConduitResolves to the current adopted revision.sync/raceways-and-conduit requires, with a flexible connection at the boiler, and control wiring shall be segregated from power wiring as the boiler manufacturer's wiring diagram requires.

16.5 Identification

16.5.1 Each boiler shall carry a permanent nameplate giving the manufacturer, model and serial number, the ASME stamping, the National Board number where registered, the maximum allowable working pressure, the rated input and gross output, the fuel and inlet pressure range, and the electrical characteristics.
16.5.2 Each boiler, its relief valve, its isolation valves, its circulator, and its fuel shutoff valve shall carry a permanent tag giving the equipment identifier from the schedule and the service.
16.5.3 Equipment and valve identification shall comply with Equipment LabelingElectrical Equipment LabelingResolves to the current adopted revision.sync/equipment-labeling and Mechanical IdentificationMechanical IdentificationResolves to the current adopted revision.sync/mechanical-identification.
16.5.4 The emergency shutoff switch at each boiler room entrance shall be labeled to identify its function and the boilers it controls.

17 Startup and Field Testing

17.1 Pre-Startup Verification

17.1.1 The Contractor shall verify before startup that the boiler has been filled, vented of air, and placed on treated water as Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current adopted revision.sync/hydronic-cleaning-and-flushing and HVAC Water TreatmentHVAC Water TreatmentResolves to the current adopted revision.sync/hvac-water-treatment require, and that the system has been cleaned and flushed before the boiler was connected.
17.1.2 The Contractor shall verify before startup that the relief valve is installed in its designated connection and that its discharge piping is complete, unobstructed, and terminated over a receptor.
17.1.3 The Contractor shall verify before startup that the static and dynamic fuel gas pressure at the appliance shutoff valve is within the range the train is built for, and that the gas train has been leak-tested.
17.1.4 The Contractor shall verify before startup that the vent and combustion air systems are complete, unobstructed, supported, sealed, and terminated as specified, and that every draft control and vent damper is wired and interlocked.
17.1.5 The Contractor shall verify before startup that the condensate drain is open and routed to its receptor and that any neutralizer contains fresh media.
17.1.6 The Contractor shall verify before startup that the electrical supply matches the boiler nameplate, that the disconnecting means and the emergency shutoff switch are installed and labeled, and that the circulator rotates in the correct direction.
17.1.7 The Contractor shall verify before startup that the jurisdictional inspection has been completed or waived in writing.
NOTE Firing a hydronic boiler on untreated water, or on a system that was never flushed, puts the construction debris of the whole system through the heat exchanger on the first day, and most heat exchanger warranties exclude the result. (17.1.8)

17.2 Startup and Combustion Setup

17.2.1 Startup of each boiler shall be performed by the technician qualified under this standard, in the presence of the Contractor and, where the Owner elects, the commissioning authority.
17.2.2 Startup shall include measurement of the dynamic fuel gas pressure at the train inlet with every boiler on the gas system at full input, and the reading shall be recorded.
17.2.3 Startup shall include setting the fuel-air ratio and performing a combustion test at high fire, at the lowest stable firing rate, and at two intermediate rates for a modulating burner, recording flue gas oxygen or carbon dioxide, carbon monoxide, oxides of nitrogen where the air district imposes a limit, stack temperature, draft or vent pressure, and combustion efficiency at each rate.
17.2.4 Startup shall include verification of the high-altitude configuration for the project elevation and its record in the startup report.
17.2.5 Startup shall include setting the operating control setpoint, the high-limit setpoint, the supply temperature reset schedule, and the plant sequencing parameters, and recording each as found and as left.
17.2.6 Startup of a dual-fuel boiler shall include the combustion test on each fuel.
17.2.7 Combustion results shall fall within the range the boiler manufacturer publishes for the model at each rate tested, and a boiler that cannot be brought within that range shall be corrected or replaced at no cost to the Owner.

17.3 Safety Device and Functional Testing

17.3.1 The safety device tests performed at startup shall be as indicated in the datasheet.
Safety Device Test Recordcheckbox
☐ Low-water cutoff test by lowering the water level or by test switch
☐ High-limit test by simulated overtemperature or overpressure
☐ Flame failure response test by interrupting the flame signal
☐ Trial for ignition timing and lockout on failure to ignite
☐ Prepurge and combustion air proving verification
☐ Safety shutoff valve leak test
☐ High and low gas pressure switch test
☐ Flow-proving or circulator interlock test
☐ Vent damper or draft proving interlock test
☐ Relief valve manual lift and reseat
☐ Emergency shutoff switch test
☐ Plant sequencing, rotation, and failover demonstration
☐ Building automation point verification
17.3.2 Each low-water cutoff shall be tested at startup by lowering the water level in the boiler or chamber, or by the test switch on a probe type, and the burner shall be shown to shut down before the water falls below the lowest safe level.
17.3.3 The high-limit control shall be tested at startup by a simulated overtemperature or overpressure condition, and the burner shall be shown to lock out and to require manual reset.
17.3.4 The flame safeguard shall be tested at startup by interrupting the flame signal with the burner firing, and the fuel safety shutoff valves shall be shown to close within the response time the controls code indicated in the datasheet permits.
17.3.5 The safety shutoff valves shall be leak-tested at startup by the method the controls code requires, and the test record shall state the method and the result.
17.3.6 Each interlock in the limit circuit shall be tested at startup by opening it with the burner firing, and the burner shall be shown to shut down and the cause to be displayed.
17.3.7 The relief valve shall be tested at startup by operation of its test lever, followed by confirmation that the valve reseats without leakage.
17.3.8 The plant sequencing shall be demonstrated at startup by staging the boilers through the full load range, by rotating the lead boiler, and by locking out a running boiler to show that the standby boiler starts.
17.3.9 Every point made available to the building automation system shall be verified at startup end to end, from the boiler controller to the operator interface, against the point list in the submittal.
17.3.10 Where a test result falls outside a specified tolerance, the Contractor shall correct the cause and retest at no cost to the Owner.
17.3.11 Where the parties disagree whether an observed condition constitutes a failed result, the Engineer of Record shall make the initial determination.
NOTE Commissioning activities beyond these tests, including trend review and seasonal testing, are the subject of CommissioningTotal Building CommissioningResolves to the current adopted revision.sync/commissioning. (17.3.12)

18 Delivery, Storage, and Handling

18.1 Boilers shall be delivered in the manufacturer's packaging with factory covers, plugs, and tags in place, and with the rigging points, lifting instructions, and operating and shipping weights marked on the unit or its crate.
18.2 The Contractor shall inspect each boiler for shipping damage on arrival at the site.
18.3 The Contractor shall report shipping damage in writing to the carrier and to the boiler manufacturer before the damaged boiler is installed.
18.4 A damaged boiler shall not be installed until the manufacturer confirms in writing that the damage does not affect its performance, listing, pressure vessel certification, or warranty.
18.5 Boilers shall be stored on level dunnage, protected from weather, construction water, and physical damage, with every opening sealed against debris entering the combustion chamber or the waterside.
18.6 A boiler set in place before the building is enclosed shall be covered and its openings sealed until the room is weathertight.
18.7 Rigging shall use only the lifting points the manufacturer designates, and no load shall be applied to the trim, the jacket, the burner, or the piping connections.
18.8 Vent components, condensate components, fuel train components, and controls shall be stored in their packaging, indoors, segregated from other trades' materials, and protected from dust and traffic.
18.9 Refractory and sectional boilers shall be handled as the manufacturer directs to avoid cracking the refractory or the sections, and a cracked section or refractory shall be replaced before the boiler is fired.

19 Warranty

19.1 The Contractor shall procure boilers carrying at least the warranty coverage indicated in the datasheet.
Warranty Period, Pressure Vessel and Heat Exchangerrange
yr
123581012152025
Warranty Period, Balance of Boilerrange
yr
1235710
19.2 The Contractor shall furnish evidence of that coverage in the closeout submittals.
19.3 Where the datasheet indicates no warranty period, the boiler shall carry the manufacturer's standard published warranty for its class, and the Contractor shall state that period in the closeout submittals.
19.4 The warranty period shall begin at substantial completion or at the date of beneficial use by the Owner, whichever is earlier.
19.5 Where a warranted component is repaired or replaced, the repaired or replaced component shall carry a fresh full warranty term running from the date of the repair, or the remainder of the original term, whichever ends later.
19.6 The Contractor shall bear the cost of removing and reinstalling adjacent work required to reach a component being repaired under warranty, and shall record the condition of that adjacent work before it is disturbed and restore it to the recorded condition.
19.7 Warranty coverage shall not be voided by water chemistry within the limits the boiler manufacturer publishes, by return water temperature within the limits the manufacturer publishes, or by condensate within the drainage arrangement specified in this standard.
19.8 Where the Owner requires the boiler to operate on water or at a return temperature outside those published limits, the Owner and the Engineer of Record shall record that condition and the protection provided in the contract documents.
19.9 The Contractor shall provide the startup, water treatment, and safety device test records the manufacturer requires to validate the warranty, and shall deliver them to the Owner with the closeout submittals.

20 Spare Parts

20.1 The Contractor shall deliver the spare parts indicated in the datasheet to the Owner at substantial completion, each marked with the identifier of the boiler it serves and stored together in a labeled container in the boiler room or in a location the Owner designates.
  • one set of ignition electrodes or one hot surface igniter for each unique burner model
  • one flame detector of each type furnished
  • one set of gaskets for each burner door, access cover, and cleaning opening opened during routine service
  • one set of fuel train filter or strainer elements for each unique train
  • one media charge for each condensate neutralizer
  • one low-water cutoff probe or float assembly for each unique cutoff model
  • one set of the fuses, relays, and sensors the boiler manufacturer lists as first-year service items
  • one gauge glass with gaskets for each unique steam boiler model
Spare Parts Deliverycheckbox
☐ Ignition electrodes or hot surface igniters
☐ Flame detectors
☐ Door, cover, and cleaning opening gaskets
☐ Fuel train filter or strainer elements
☐ Condensate neutralizer media charges
☐ Low-water cutoff probe or float assemblies
☐ Fuses, relays, and sensors
☐ Gauge glasses with gaskets
20.2 Where several boilers of the same model are furnished, common wear parts shall be stocked once for the plant rather than once per boiler, unless the datasheet indicates otherwise.
20.3 The Contractor shall obtain the Owner's signed receipt for the spare parts delivered.