Navien NHB Series, Installation & Operation Manual

Page: 84 / 135

84 Installing a Common Vent System
To install a condensate drain to the cascade system:
1. Form a loop with a drain hose and fix it with a tie.
Note
Ɣ
While shaping the hose, do not bend the hose
excessively. The hose will be deformed and the flow
will be restricted if the hose is bent in sharp angles.
Ɣ
Do not fix the hose too tight when tying the hose
to form the loop. The hose will be deformed and
the flow will be restricted if the tie is too tight.
2. Prime the loop using tap water.
3. Install the hose to the cascade system and direct the end of the
hose to a drain.
WARNING
After installing the condensate drain hose, check the loop
again to ensure that the prime water is not spilled. The loop
(siphon) must be primed with water before running the
system to prevent toxic exhaust gas from leaking into the
installation site.
9.7 Installing a Condensate Drain
Refer to the following examples to install a condensate drain hose
(field supplied) to the common vent system. The condensate
drain hose prevents condensate or rain from entering the exhaust
system and gathering above the backflow damper.
Exhaust
Exhaust
End
Cap
End
Cap
Siphon Loop
Siphon Loop
Drain Hose
Drain hose
Drain
Drain
Intake
Intake