Maintaining The Boiler; Cleaning The Boiler; Draining The Boiler - Navien NCB-20LHWE Installation & Operation Manual

12. Maintaining the Boiler

12.1 Cleaning the Boiler

CAUTION
Make sure the boiler is turned o and the power supply is
disconnected before cleaning the boiler. The boiler may
remain hot for several minutes after it is turned o . 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.

12.2 Draining the Boiler

You will need to drain either both the space heating side
and domestic hot water (DHW) side, or one side only before
performing maintenance tasks, such as cleaning the adapter
lter, or to prevent the boiler from freezing when it will not be
used for an extended period.
Refer to the "2.5 Dimensions" on page 15 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 on the front panel to turn o the
boiler.
56 Maintaining the Boiler
3. Disconnect the power supply from the boiler.
4. Close the gas valve.
Gas Valve
5. Close the water supply valve on the inlet to the boiler. If
there is no valve, turn o the water supply at the water main.
Opened Closed