Navien NHW700 User's Information Manual page 20

To flush the Heat Exchanger:
A
C
Hot Water Line
Circulation Pump
Flushing Kit
1. Press the Power button on the front panel to
turn off the water heater.
2. Disconnect the power supply to the water
heater.
3. Close the "C" and "D" valves on the hot and cold
water lines.
4. Connect one tube to the "A" valve and place the
free end in the bucket.
5. Connect one of the tubes to the circulation
pump outlet and the cold water line at the "B"
valve.
6. Connect one tube to the circulation pump inlet
and place the free end in the bucket.
7. Pour the cleaning solution into the bucket.
8. Open both "A" and "B" valves.
9. Turn on the circulation pump and allow the
solution to circulate through the water heater
for at least 45 minutes.
B
A
C D
Navien Plumb
Easy Valve Kit
B
D
Cold Water Line
10. Rinse the cleaning solution from the water
heater:
a. Remove the free end of the drain tube from
the bucket and place it in the condensate
drain or laundry tub (wherever the water
heater drains).
b. Close the "B" valve and open the "D" valve. Do
not open the "C" valve yet.
c. Allow water to flow through the water heater
for 5 minutes.
d. Close the "A" valve and open the "C" valve.
11. Disconnect all tubes.
12. Remove the cold water inlet filter from the water
heater and clean out any residue.
13. Reinsert the filter and ensure the filter cap is
securely tightened.
14. Reconnect the power supply to the Water
Heater.
15. Press the Power button on the front panel to
turn on the water heater.
Maintaining the Water Heater 19