Williamson-Thermoflo GWC-070 Manual page 40

GWC -
gas fired water boiler
DIRECT VENT —
Install termination — concentric pipes
1. Assemble the vent termination as described for concentric termi-
nations, on page 45.
If necessary, you can shorten the lengths of the inner and
outer pipes for a shorter finished assembly. But you must
ensure the pipes butt correctly at both ends. Failure to
properly assemble the concentric termination can result
in flue gas recirculation, causing possible severe personal
injury or death.
2. Wall penetration:
a. 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 48.
3. Secure the termination in place so the rain cap will butt against the
outside wall or outer thimble plate as shown in Figure 48, page 40.
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 48, page 40.
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 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 wall 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 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 a bird screen (supplied with
boiler) and rain cap as follows:
a. Place the bird screen on the end of the inner pipe as in Fig-
ure 54, page 45.
b. Cement the rain cap in place as shown.
40
— Boiler Manual
Sidewall with 3" concentric
Figure 47
Figure 48
(continued)
Termination location — concentric
termination — multiple boilers —
clearance from vent of one to air intake of
the next
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 550-142-056/0411