Installation Guide

Part number 550-100-066/0608
45
g a s -f i r e d w at e r b o i l e r — Boiler Manual
Vertical vent/air termination: 3” PVC concentric (continued)
For each joint:10.
Handle fittings and pipes carefully to prevent contamination of a.
surfaces.
Apply primer liberally to both joint surfaces — pipe end and fit-b.
ting socket.
While primer is still damp, lightly apply approved cement to both c.
surfaces in a uniform coating.
Apply a second coat to both surfaces. Avoid using too much cement d.
on sockets to prevent cement buildup inside.
With cement still wet, insert pipe into fitting, twisting ¼ turn. Make e.
sure pipe is fully inserted.
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 ue gas recirculation,
causing possible severe personal injury or death.
Mount concentric termination
Before beginning vent and air piping from boiler, mount and secure 1.
the concentric termination as shown in Figure 60.
The vent and air piping must be securely supported, and must
not rest its weight on the boiler fittings. DO NOT drill or
screw into either the vent pipe or air pipe. 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.
When inserting the partially-assembled termination kit
through the roof penetration, wrap plastic or other protection
over the end of the exposed assembly to prevent 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 as-
sembly 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 ue product
emissions.
When using AL294C stainless vent pipe, use the vent pipe
manufacturer’s 3-inch PVC adapter when connecting to the
concentric vent attachment.
After the assembly has been positioned in the roof opening and all 2.
supports have been attached, install the bird screen and rain cap as
follows:
Place the bird screen on the end of the inner pipe as in a. Fig-
ure 59, page 44.
Cement the rain cap in place as shown.b.
Vent termination support
Support the concentric vent/air termination at the roof penetration 1.
as shown in Figure 60.
The supports/bracing used must support the termination assembly •
to prevent vertical slippage or sideways 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.
Weil-McLain 3” PVC concentric 
termination supports
Alternate piping configuration, using (3) 
45-degree elbows to obtain closer pipe
centers