Navien NBH Series, User'S Information Manual

Page: 12 / 27

12 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 before performing maintenance
tasks, such as to prevent the boiler from freezing when it will not
be used for an extended period.
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 on the front panel to turn off the boiler.
MODE
3. Close the gas valve.
Gas Valve
Open Closed
4. Close the water supply valve and the return valves on the
manifold system.
4. Maintaining the Boiler