Weil-McLain WM97+70 Manual page 28

WM97+ -
gas fired water boiler
DIRECT VENT —
All vent pipes and air inlets must terminate at the same
height to avoid possibility of severe personal injury, death
or substantial property damage.
2. Place wall penetrations to obtain minimum clearances shown in
Figure 26, page 28 for U. S. installations. For Canadian installations,
provide clearances required by CSA B149.1 or B149.2 Installation
Code and a ULC S636 compliant vent kit.
3. The air inlet of a WM97+ boiler is part of a direct vent connection.
It is not classified as a forced air intake with regard to spacing from
adjacent boiler vents.
Prepare wall penetrations
1. Air pipe penetration:
a. Cut a hole for the air pipe. Size the air pipe hole as close as
desired to the air pipe outside diameter.
2. Vent pipe penetration:
a. Cut a hole for the vent pipe. For either combustible or non-
combustible construction, size the vent pipe hole at least 0.4"
larger than the vent pipe diameter.
b. Insert a galvanized metal thimble in the vent pipe hole as
shown in Figure 27.
3. Use a sidewall termination plate as a template for correct location
of hole centers.
a. Sidewall termination plates for 3" PVC piping are included
with the Weil-McLain sidewall vent/air plate kit, shipped with
each boiler.
b. For 3" AL29-4C vent pipe (with 3" PVC air pipe) or for 2"
PVC vent/air piping, purchase optional sidewall separate pipes
plate kit.
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. (See Figure 25, page 27.) Bird screens
must be purchased separately. See the parts list at the end of this
manual for part numbers.
2. When completed, the air termination coupling 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 25, page 27.
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 25, page 27.
4. Maintain the required dimensions of the finished termination
piping as shown in Figure 25, page 27.
5. For multiple boiler terminations, see Figure 26, page 28.
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.
– 28 –
— Boiler Manual
Sidewall with separate pipes
See notices on previous page.
Multiple separate pipes sidewall terminations
Figure 26
— maintain vertical spacing between vent and
air fittings shown in Figure 25, page 27
Sidewall termination assembly — using
Figure 27
separate pipes
1 Vent piping
2 Air piping
3 Sidewall termination plates: for 3" PVC,
use plates supplied with boiler in W-M
vent/air plate kit; for 3" AL29-4C or 2" PVC,
purchase optional sidewall separate pipes
plate kit
(continued)
4 Galvanized thimbles, by in-
staller
5 Bird screen, by installer
6 Air inlet elbow
7 Elbow
8 Nipple
9 Elbow (vent termination)
Part number 550-142-085/0712