Installation & Operation Manual
5Vertical direct venting
Vent/air termination – vertical
WARNING
WARNING
NOTICE
Follow instructions below when determining vent location to avoid possibility of severe personal injury, death or substantial property damage.
Do not connect any other appliance to the vent pipe or multiple boilers to a common vent pipe. Failure to comply could result in severe personal injury, death, or substantial property damage.
Installation must comply with local requirements and with the National Fuel Gas Code, ANSI Z223.1 for U.S. installations or CSA B149.1 for Canadian installations.
WARNING Rooftop vent and air inlet terminations must terminate in the same pressure zone,
unless vertical vent sidewall air is set up as shown in the General Venting - Vertical Vent, Sidewall Air Section.
Figure
ALTERNATE INTAKE LOCATIONS:
INTAKE PIPES MAY BE LOCATED
ANYWHERE WITHIN 24" (610 MM)
OF VENT PIPE
BIRD SCREEN
(TYPICAL)
VENT
Determine location
Locate the vent/air terminations using the following guidelines:
1. The total length of piping for vent or air must not exceed |
the limits given in the General Venting Section on page 21 |
of this manual. |
COUPLING (FIELD SUPPLIED)
VENT OUTLET
12" MINIMUM ABOVE AIR INLET
6" (152 MM) MINIMUM 
ABOVE ROOF /
SNOW LINE
COMBUSTION
AIR
2. The vent must terminate at least 3 feet above the highest |
place in which the vent penetrates the roof and at least |
2 feet above any part of a building within 10 horizontal |
feet. |
3. The air piping must terminate in a |
return pipe no further than 2 feet (.6 m) from the center |
of the vent pipe. This placement avoids recirculation of |
flue products into the combustion air stream. |
4. The vent piping must terminate in an |
as shown in FIG. |
at least 1 foot above the air intake. When the vent |
termination uses a rain cap as illustrated in FIG. |
maintain at least 36" (914 mm) above the air inlet. The |
air inlet pipe and vent pipe can be located in any desired |
position on the roof, but must always be no further than |
2 feet (.6 m) apart and with the vent termination at least |
1 foot above the air intake. |
Figure
ALTERNATE INTAKE LOCATIONS:
INTAKE PIPES MAY BE LOCATED
ANYWHERE WITHIN 24” (610 MM)
OF VENT PIPE
VENT | BIRD SCREEN |
(TYPICAL) |
6" (152 MM) MINIMUM
ABOVE ROOF /
SNOW LINE
COM,BUSTION
AIR
VENT OUTLET
36” (914 MM) MINIMUM
ABOVE AIR INLET
5.Locate terminations so they are not likely to be damaged by foreign objects, such as stones or balls, or subject to buildup of leaves or sediment.
30 
