Cleaning The Air Intake Filter - Navien NBH Series User's Information Manual

5. Remove the drain cap on the manifold system to drain the
boiler.
Drain Cap
Place a bucket under the boiler to gather water
Note
released from the manifold system.
Do not allow the pump to become wet.

4.3 Cleaning the Air Intake Filter

If the air intake filter becomes clogged by dust or lint, the boiler
will cease to operate and "Error Code 110" will appear on the front
panel display. To properly maintain the boiler, clean the air intake
filter every 3-4 months.
To clean the air intake filter:
1. Press the Power button on the front panel to turn off the boiler.
Drain Cap
2. Disconnect the power supply to the boiler.
3. Remove the front cover of the boiler.
MODE
Maintaining the Boiler 13