Weil-McLain Ultra Manual page 38

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gas fired water boiler
Sidewall vent/air termination:
2. Wall penetration — Preferably, use a thimble with a 4½-inch hole.
If not using a thimble, carefully use a hole saw to cut a hole not
larger than 4¾ inches in diameter through the wall. The finished
hole must provide a solid stop for the rain cap ribs, as shown in
the inset to Figure 47, page 38.
3. Secure the termination in place so the rain cap will butt against the
outside wall or outer thimble plate as shown in Figure 47.
4. Before beginning vent and air piping from the boiler to the con-
centric termination, mount and secure the concentric termination
as shown in Figure 47.
The vent and air piping must be securely supported, and
must not rest its weight on the boiler fittings. Failure to
properly support the vent and air piping could result in
vent piping damage, resulting in possible severe personal
injury, death or substantial property damage.
The supports/bracing used must support the termination
assembly to prevent vertical slippage or movement.
The clamps used on the outside of the termination pipe
must not cut into the pipe or contain sharp edges that
could cause a crack to form.
When inserting the partially-assembled termination
kit through the roof penetration, wrap plastic or other
protection over the end of the exposed assembly to pre-
vent debris from entering the pipes. If the air passages
become blocked, the boiler will not operate. Once the
rain cap has been cemented to the assembly, there is no
way to correct the problem. The assembly would have
to be replaced if it were cut to be removed and cleaned.
Altering the assembly in any way could result in severe
personal injury or death due to toxic flue product emis-
sions.
When using AL294C stainless vent pipe, use the vent pipe
manufacturer's 3-inch PVC adapter when connecting to
the concentric vent attachment.
5. After the assembly has been positioned in the opening and all
supports have been attached, install the bird screen and rain cap
as follows:
a. Place the bird screen on the end of the inner pipe as in
ure 59, page 44.
b. Cement the rain cap in place as shown.
38
— Boiler Manual
Figure 47
Fig-
3" PVC concentric
Installing and supporting the concentric
sidewall vent assembly
Ensure that the wall material is strong enough
to prevent the rain cap from being pushed
inward if struck or pushed from the outside.
Part number 550-100-066/0608
(continued)