Maintaining The Boiler; Cleaning The Boiler; Draining The Boiler - Navien NFB-175H User's Information Manual

4. Maintaining the Boiler

4.1 Cleaning the Boiler

CAUTION
Make sure the boiler is turned off and the power
supply is disconnected before cleaning the
boiler. The boiler may remain hot for several
minutes after it is turned off. To prevent burns,
wait until the boiler has cooled down before
cleaning.
To clean the boiler, wipe the outside with a damp
cloth. Use a non-acidic, non-abrasive cleaner
to remove any surface stains. The front panel is
moisture resistant, but it is not waterproof. Keep it as
dry as possible.

4.2 Draining the Boiler

You will need to drain the boiler under certain
circumstances such as when the boiler is not used
for an extended period of time in order to prevent
freeze damage.
Refer to "2.2 Parts of the Boiler" on page 6 for
details about part locations.
To drain the boiler:
1. Place a bucket under the boiler to collect the
residual water inside the boiler.
2. Press the Power button (
to turn off the boiler.
14 Maintaining the Boiler
) on the front panel
3. Close the gas valve.
OPEN
CLOSE
Gas Valve
4. Close the water supply valve and the return
valves on the manifold system.
OPEN
CLOSE
Closed
Open