Installation manual

24
In Canada construct all combustion air and vent pipes for this unit of CSA or ULC certified
schedule-40 CPVC, schedule-40 PVC, PVC-DWV or ABS-DWV pipe and pipe cement. SDR
pipe is NOT approved in Canada.
COMBUSTION AIR AND VENT PIPE
3. Combustion air and vent piping connections
on boiler are sized for 2” pipe. Any pipe size
change (to 3”) must be made outside of the
boiler casing in a vertical run of pipe to allow
for proper drainage of vent condensate. Due
to potential for flue gas temperatures over
155°F, the first five (5) feet of vent pipe must
be CPVC, the remaining vent pipe can be
PVC. If any elbows are employed within the
first 5 feet of vent, they must be CPVC too.
Two (2) - 30” pieces of 2” CPVC pipe are
furnished with the boiler.
NOTE: The
transition from 2” pipe to 3” pipe
must be made in a vertical run.
4. Combustion air and vent piping lengths,
The first 5 feet of “TOTAL EQUIVALENT LENGTH” of vent piping run must be CPVC:
The length of pipe is counted from the boiler jacket (air intake pipe) or from vent tee (vent pipe).
For additional elbows, reduce the maximum vent length as shown:
2” 90 degree elbow -1 ½ feet per additional elbow.
3” 90 degree elbow - 3 feet per additional elbow.
Example: To add 2 additional 90 degree elbows to a 3” pipe for a 75 boiler.
Each elbow is 3 additional feet per 90 degree elbow for a total of 6 feet. (1 elbow @ 3 feet
+ 1 elbow @ 3 feet = 6 additional feet of pipe) The total additional pipe is then subtracted
from the maximum allowable pipe length to give the new maximum length of 94 feet with 6,
90 degree elbows. (“TOTAL EQUIVALENT LENGTH”: Original 100 feet max. - 6 feet for 2
additional elbows = new 94 feet maximum length).
5. Combustion air and vent piping to be pitched
back to boiler at minimum ¼” per foot from
intake and vent terminals so that all moisture
in combustion air and vent piping drains to
boiler. Pipes must be pitched continuously
with no sags or low spots where moisture
can accumulate and block the flow of air
or flue gas. Combustion air and vent pipes
must be airtight and watertight.
BOILER
SIZE
2” PIPE MINIMUM
VENTING
2” PIPE MAXIMUM
VENTING”
3” PIPE MINIMUM
VENTING
3” PIPE MAXIMUM
VENTING”
100
2 FEET IN LENGTH
+
4-90º ELBOWS
15 FEET
IN LENGTH
AND UP TO
4-90º ELBOWS
15 FEET IN LENGTH
+
4-90º ELBOWS
80 FEET IN LENGTH
AND UP TO
4-90º ELBOWS
75 & 50
2 FEET IN LENGTH
+
4-90º ELBOWS
20 FEET
IN LENGTH
AND UP TO
4-90º ELBOWS
20 FEET IN LENGTH
+
4-90º ELBOWS
100 FEET IN LENGTH
AND UP TO
4-90º ELBOWS