Navien NHB Series Installation & Operation Manual page 79

9.3.2 Connecting the Pipe to the Damper
1. Measure 3-1/8" from the end of the vent pipe, then draw a mark
at that distance.
Mark 3-1/8" from
the end of the pipe
2. Insert the vent pipe into the vent collar to start the vent run.
Make sure to completely slide the vent into the collar until the
end makes contact with the bottom of the socket.
Verify that 3-1/8" of the pipe has been completely
Note
inserted into the collar and that the mark is no
longer visible.
WARNING
Ensure that the vent pipe is properly beveled prior to installation
and that the pipe is fully connected to the exhaust gas vent
fitting. Failure to properly bevel and install the pipe can lead to
gasket failure and flue gas leakage, which may result in serious
injury or death.
90°
3. Tighten the clamp with a screwdriver to properly seal the joint.
3-1/8"
Do not start the vent run with a street elbow at the vent collar.
Using an elbow directly at the collar will not allow for a tight
seal between the appliances and vent pipe. A length of straight
pipe must be used when starting the vent run.
Note
CAUTION
The length of vent pipe from the unit to the common
vent main trunk pipe must not exceed 12' of
equivalent length.
Installing a Common Vent System 79