Installing A Condensate Drain - Navien NFB-175 Mode D'emploi

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.
Intake
End
Cap
End
Cap
Siphon loop
Exhaust
Siphon loop
Drain hose
Drain
Exhaust
Intake
Drain hose
Drain
To install a condensate drain to the cascade system:
1. Form a loop with a drain hose and fix it with a tie.
While shaping the hose, do not bend the hose
Note
●
excessively. The hose will be deformed and the flow
will be restricted if the hose is bent in sharp angles.
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.
Installing a Common Vent System 77