Type B Draft Hood Connectors; Residential Standard Gas Water Heater Service Handbook - A.O. Smith GCV300 Service Handbook

• When transition to a larger vent
size is required, the vent transition
connection must be made at the
draft hood outlet. Do not connect
a 4-inch draft hood to 3-inch vent
pipe. A draft hood must only be
connected to an equal or larger-
sized vent pipe (as allowed by code).
Only use the draft hood that is supplied
with the water heater.
4-inch Vent Pipe
of vent pipe
Increaser
Figure 34.
• When two vent pipes are made by
different manufacturers, they may
not fit together properly. In such
cases, use a universal adapter to
join the vent pipes. (Follow the
manufacturer's instructions and all
applicable code.) However, do not
use a universal adapter to join the
draft hood to the vent pipe. Always
verify that the vent connections are
secure and air tight.
28 • Residential Standard Gas Water Heater Service Handbook
Type B Dra Hood Connectors
Double wall (Type B) vent pipe will not
fit draft hoods properly. To ensure a
secure connection, use a Type B draft
hood connector between double wall
vent pipe and the draft hood.
Type B vent connectors are available
in various sizes, including those shown
below.
3-Inch Type B 4-Inch Type B
Connector Connector
Figure 35.
Figure 36 shows a typical connection
between a draft hood and Type B vent
pipe.
ype B
Figure 36.
NOTE: Be sure to secure
connections as described in step 3 of
the Installation Procedure section.
the