Williamson-Thermoflo GWC-070 Manual page 38

GWC -
gas fired water boiler
DIRECT VENT —
For multiple boiler applications using the manifolded
combustion air option, the vent can be terminated in
an elbow as in Figure 43, page 37, or in a coupling or
sidewall termination plate. The vents must be located
following the restrictions in Figure 41, page 35
Figure 38, page 31.
In addition to the vent materials, this installation requires
two (2) W-T sidewall termination plates and a bird screen
for each air and vent termination fitting, unless using an
AL29-4C vent termination fitting with integral screen. Two
plates and two bird screens are supplied with the boiler.
Prepare wall penetrations
1. Two W-T sidewall termination plates are included with each boiler.
Use one of the sidewall termination plates as a template to mark
air pipe and vent pipe hole locations.
a. Hole centers in the plates are 3¾" apart.
b. Hole diameters are 3.14" for holes as is. Use as is for 3" AL29-4C
pipe. Remove knockout to provide 3
2. Air pipe penetration:
a. Cut a hole for the air pipe.
b. Size the air pipe hole as close as desired to the air pipe outside
diameter.
3. Vent pipe penetration:
a. Cut a hole for the vent pipe.
b. Cut the vent pipe hole to at least 3.9 inches for 3" PVC vent or
3.4" for 3" AL29-4C vent.
c. Insert a galvanized metal thimble in the vent pipe hole as
shown in Figure 45.
4. Follow all local codes for isolation of vent pipe when passing
through floors or walls.
5. Seal exterior openings thoroughly with exterior caulk.
Termination and fittings
1. Prepare the vent termination elbow and the air termination elbow
by inserting bird screens, unless using an AL29-4C vent termina-
tion fitting with integral screen. (See Figure 43, page 37.) Two bird
screens are supplied with the boiler.
2. When completed, the air termination elbow opening must be
oriented at least 12 inches below the vent termination and at least
12 inches above grade or snow line as shown in Figure 43, page 37.
3. You can orient the vent termination elbow either directly out-
ward or 90 degrees away from the air inlet elbow as shown in
Figure 43, page 37.
4. Maintain the required dimensions of the finished termination
piping as shown in Figure 43, page 37.
5. For multiple boiler terminations, see Figure 44, page 38.
6. Do not extend exposed vent pipe outside of building more than
shown in this document. Condensate could freeze and block vent
pipe.
If extending the vent and air pipes out from the wall,
install a coupling on each pipe. Mount the piping with
the coupling flush with the outer plate.
38
— Boiler Manual
Sidewall with separate pipes
and
⁄ " hole for 3" PVC pipe.
5
8
Multiple separate pipes sidewall terminations
Figure 44
Sidewall termination assembly — using
Figure 45
separate pipes
1 Vent piping
2 Air piping
3 W-T sidewall termination plates, supplied
with boiler (remove knockout if using PVC
pipe; leave knockout in if using AL29-4C
vent pipe)
4 Galvanized thimbles, by installer
(continued)
5 Bird screens, supplied with
boiler
6 Air inlet elbow
7 Elbow
8 Nipple
9 Elbow (vent termination)
Part number 550-142-056/0411