M3
CONDENSING WATER BOILER
16
34-1115 12/15
5. Install a manual main gas shutoff valve on the gas supply piping connected to the appliance to isolate the burner
and gas train from the main supply gas in compliance with NFPA 54 National Fuel Gas Code and most local
Codes.
6. The gas system installer must clearly identify the emergency shut-off device.
7. A sediment trap (drip leg) MUST be provided in the inlet of the gas connection to the unit.
8. The combination gas valves and/or gas regulators incorporate either an internal vent limiter or an externally
mounted vent limiting orifice and 1/4" aluminum tube located in a “T” attached to the regulator vent port. Venting
to outdoors is not required. Never remove, cut, splice or alter the flexible tubing attached directly to the regulator
vent port or to a vent limiting fitting attached externally to the regulator, as this will cause unreliable ignition and
can cause improper operation.
Although not required, a connection to the open end of the 1/4" aluminum tube can be made and routed to the
outdoors. No other connection point is allowed. Do not remove the aluminum tubing and connect directly to the
“T”, as damage to the required vent limiter and improper gas control could result.
7 COMBUSTION AND VENTILATION AIR
Provisions for adequate combustion and ventilation air to the mechanical room must be in accordance with Section
“Air for Combustion and Ventilation” in the latest edition of the NFPA 54 National Fuel Gas Code, ANSI Z223.1
and/or CAN/CSA B149, Installation Codes or applicable provisions of the local building codes. Any method
addressed in NFPA 54 National Fuel Gas Code section “Air for Combustion and Ventilation is acceptable and
several are outlined below.
7.1 Equipment Located In Confined Spaces
Equipment located in confined spaces requires two openings, one commencing within 12” (30.5 cm) from the top of
the enclosure/room and one commencing within 12” from bottom of the enclosure/room to assure adequate
combustion air and proper ventilation. The total input of all gas utilization equipment installed in the room must be
used to determine the required minimum air volume needed for combustion, ventilation and dilution of flue gasses.
Also consider makeup air requirements from other equipment within the mechanical room or other rooms that are
pressure connected with the mechanical room. Some examples of other makeup air requirements are from kitchen
exhaust hoods, clothes dryers, powered exhaust fans, etc.
• All Air From Outdoors:
Each opening requires a minimum free area of 1 square inch
per 4000 Btu/hr of the total input rating of all
appliances in the enclosure, if directly communicating with the outdoors or communicating to the outdoors
through vertical ducts.
Each opening requires a minimum free area of 1 square inch
per 2000 Btu/hr of the total input rating of all
appliances in the enclosure, if communicating with the outdoors through horizontal ducts.
• All Air From Inside The Building:
Follow the requirements of NFPA 54 National Fuel Gas Code, ANSI Z223.1 section “Indoor Combustion Air.”
• Combination Of Air From The Indoors And From The Outdoors:
Follow the requirements of NFPA National Fuel Gas Code, ANSI Z223.1 section “Combination Indoor and
Outdoor Combustion Air.”
• From Outdoors Through One Opening:
Follow the requirements of NFPA National Fuel Gas Code, ANSI Z223.1 section “One Permanent Opening
Method.”
NOTE: This unit may be installed with a remote air intake system which uses a make-up air duct to draw combustion
air directly from outdoors.
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