Flushing The Heat Exchanger - Navien NPE-210A Operation Manual

6. Remove the recirculation inlet filter from the bottom of the
water heater ("A" model only).
Recirculation
Inlet Filter
("A" model only)
Pump Drain Plug
("A" model only)
7. Open the pump drain plug ("A" model only).
8. Remove the cold water inlet filter.
9. Allow the residual water to drain from the water heater.
10. When the water is completely drained, reinsert the
recirculation inlet filter and the cold water inlet filter, and then
close the pump drain plug.
11. To refill the water heater follow the steps of "Draining the
Water Heater" in reverse.

4.3 Flushing the Heat Exchanger

Flushing the Heat Exchanger is a somewhat complicated
procedure. Read the following instructions carefully before
attempting this procedure. If you are uncertain about any of
the steps in the procedure, contact an authorized technician or
licensed professional. Keep in mind that improper maintenance
can void your warranty.
Refer to the "2.2 Parts of the Water Heater" on page 6 for
details about part locations.
Before flushing the Heat Exchanger, gather the following items:
Cold Water
A bucket that is 5 gallons or larger
Inlet Filter
Cleaning solution diluted with water
3 hoses
A water circulation pump
To flush the Heat Exchanger:
Flushing Kit
CAUTION
A
B
C
D
Hot Water Line
Circulation Pump
B
A
C D
Navien Easy valve Kit
Cold Water Line
Maintaining the Water Heater 11