Operating instructions
28
Doors &
Windows
Combustion air and vent termination 
must be 12" (305mm) from or below 
doors, windows or gravity inlet.
Forced Air 
Inlet
Terminate venting system 3’ (0.9m) 
above and 10' (3.0m) from any forced 
air inlet (except boiler’s combustion 
air inlet).
"L" 
Corner
Vent termination shall NOT be installed 
closer than 3' (0.9m) from inside 
corner of “L” shaped structure. 
Grade, Snow 
& Ice
Terminate vent system bottom, 
minimum 12" (300 mm) above highest 
anticipated snow level.
Avoid locations where snow may drift 
and block vent and combustion air. Ice 
or snow may cause boiler to shut down 
if vent or combustion air becomes 
obstructed.
Condensate
Vent gas may condense, forming 
moisture, may be corrosive. Protect 
building materials at vent from exhaust 
of vent gas. 
Termination must be 
12" (305mm) from 
or below doors, 
windows or gravity 
inlet.
12" 
(305mm) 
Minimum
Termination
Forced Air 
Inlet
3' (0.9m) 
[If located 
within  10'  (3m) 
of forced air 
inlet]
Termination
Less than 
10' (3m) 
Minimum 
3' (0.9m) 
Minimum
FIGURE 6-12 
FIGURE 6-13 
FIGURE 6-14 
6.7 Side Venting Terminal Requirements of :
• USA - National Fuel Gas Code, ANSI 223.1/NFPA 54.
• Canada - Natural Gas and Propane Installation Code, CAN/CSA B149.1
Venting terminal from doors and windows See gure 6-12
Venting terminal from forced air inlet of other appliances See gure 6-13
Venting terminal from snow level See gure 6-14
Venting terminal from vegetation See gure 6-15
Venting terminal from public walkway See gure 6-16
6 - COMBUSTION AIR AND VENT PIPING










