Installing A Condensate Drain - Navien NFC-250/175H Installation Manual

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
Siphon loop
End
Cap
Exhaust
Drain hose
Drain
Exhaust
Intake
Siphon loop
Drain hose
Drain
To install a condensate drain to the common vent
system:
1. Form a loop with a drain hose and fix it with a
tie.
While shaping the hose, do not
Note
●
bend the hose 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 common vent system and
direct the end of the hose to a drain.
7.9 in
(200 mm)
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 101