20
PHTM II
Combi Installation, Operating & Service Instructions
110331-07 - 8/23
7
General Venting
(continued)
6. CPVC/PVC vent starter kits are available. Kits
include 30 in. (760 mm) CPVC pipe, 90° short
CPVC elbow, PVC coupling (vent terminal), 90°
short PVC elbow (air terminal), and 2 terminal
screens. Components in these kits are not
ULC-S636 listed and are therefore not usable in
Canada.
A. 2 in. kit: 107039-01
B. 3 in. kit: 111945-01
7. Allow for 3/8 in. (9.5 mm) of thermal expansion per
10 ft. (3.0 m) of CPVC/PVC pipe. If a straight run
of pipe exceeds 20 ft. (6.0 m) and is restrained at
both ends, an offset or expansion loop is required
per Figure 7-15. If a straight horizontal run of pipe
exceeds 20 ft. (6.0 m) and is restrained at one
end with an elbow at the other, ensure hanger or
guide is not less than Y in from elbow per Figure
7-15. Thermal expansion fittings not permitted.
8. All air piping may be PVC.
9. Vent and air can be up-sized to 3 in. for
longer runs. If upsizing to 3 in. vent material, the
following is required:
A. 2 in. CPVC vent piece (max 12 in. 305 mm)
(field supplied).
B. 2 in. x 3 in. CPVC increaser (field supplied,
Lasco 9829-338, Spears 829-338C or IPEX
9829338 or equivalent).
C. 3 in CPVC/PVC vent starter kit (purchased
separately, see above).
D. Similar PVC fittings for air intake.
NOTICE:
Increaser must be installed in vertical
section of pipe. See Figure 7-13.
10. Cut pipe squarely and debur inside and outside of
pipe ends after cutting.
11. Dry fit all vent and air components before
cementing any joints.
12. Use field supplied primer and cement
appropriate for materials being joined. Follow
primer and cement instructions to join pipe and
fittings.
13. Clean all pipe ends and fittings with appropriate
primer before cement. Apply primer to both pipe
and fitting socket before applying cement.
14. Boiler vent connector is gasketed. Lubricate
gasket with soapy water, insert pipe until it
bottoms out, and tighten clamp.
15. Boiler air connector in PVC socket fitting. Drill
7/32 in. (5.5 mm) hole in air connector. Drill
1/8 in. (3.2 mm) hole in air pipe to align with hole
in connector. Insert pipe into air connector and
At least 30in. (760mm)
of CPVC pipe and one
CPVC elbow required
between boiler and PVC
vent piping.
PVC coupling may
be used to join CPVC
to PVC vent pipe.
Clamp
To vent
termination
From air
termination
Max. 12in. (305mm)
2in. CPVC pipe
3in. X 2in. CPVC
Increaser
At least 30in. (760mm) of
CPVC pipe and one CPVC
elbow required between
boiler and PVC vent piping.
PVC coupling may
be used to join CPVC
to PVC vent piping.
3in. X 2in. PVC
Increaser
Clamp
Max. 12in. (305mm)
2in. PVC pipe
To vent
termination
From air
termination
Figure 7-12: Near Boiler CPVC/PVC Venting
Figure 7-13: Near Boiler CPVC/PVC Venting with
Increaser
Note: Length of 2 in. pipe is counted toward 30 in.
CPVC requirement.
use #10 x 1 in. sheet metal screw to secure. Seal
joint between air connector and pipe with RTV
silicone.
16. To the extent possible, slope horizontal air
piping towards outdoors.
