16
Procedure for Flushing the Heat Exchanger
If the error code “C #*~C #*” is flashing on the Remote Controller (or Operation Panel**), it means
there is Scale Build-up in the Heat Exchanger.The Heat Exchanger needs to be flushed*** to
remove the Scale Build-up.
Damage to the water heater due to Scale Build-up is not covered by the water heater's warranty.
To clear the error code “C #*~C #*”, the Heat Exchanger must be flushed.
If the error code “C #*” is displayed and flashing on the Remote Controller (or Operation Panel**),
please contact Noritz America (866-766-7489).
*
= 1, 2, 3, 4, F
#
= 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
** NR98DVC(GQ-2857WX-FFA US) and NR83DVC(GQ-2457WS-FFA US) only.
*** Connect the blue connector marked "FLUSH" for flushing near the Circuit Board when flushing the Heat Exchanger.
After connecting it, the water heater is set to “Flushing Mode”.
㻮㼍㼟㼕㼏㻌㻼㼞㼛㼏㼑㼐㼡㼞㼑
䍾㻼㼞㼛㼏㼑㼐㼡㼞㼑㻌䠍㻚㻌
The preparation of the flushing system
䍿
1. Close the gas supply valve.
2. Close the water inlet valve (V1) and the water outlet valve (V2).
3. Connect the one drain hose (H1) to the drain valve (V3), and then the other to the
circulating pump.
4. Connect the drain hose (H2) to the circulating pump.
5. Connect the drain hose (H3) to the drain valve (V4).
6. Pour 1 gallon of “
㻯㼍㼘㼏㼕㼡㼙㻘㻌㻸㼕㼙㼑㻌㼍㼚㼐㻌㻾㼡㼟㼠㻌㻾㼑㼙㼛㼢㼍㼘㻌㻼㼞㼛㼐㼡㼏㼠
” and
㻝㻌
gallon water into the bucket.
Noritz recommends “
㻯㼍㼘㼏㼕㼡㼙㻘㻌㻸㼕㼙㼑㻌㼍㼚㼐㻌㻾㼡㼟㼠㻌㻾㼑㼙㼛㼢㼍㼘㻌㻼㼞㼛㼐㼡㼏㼠
”
㻌
for flushing.
7. Place the both drain hoses (H2 and H3) into the bucket filled with the flushing solution.
8. Open the both drain valves (V3 and V4).
The water heater must remain connected to electrical power
when flushing the Heat Exchanger.
**** Isolation valves may be purchased as an accessory from
㻌㼍㼚㻌㼍㼡㼠㼔㼛㼞㼕㼦㼑㼐㻌㻺㼛㼞㼕㼠㼦㻌㼣㼔㼛㼘㼑㼟㼍㼘㼑㼞
.
They allow for full diagnostic testing and easy flushing of the system
㻚
㻌㻌㻌㻌㻌㻌㻯㼛㼚㼠㼍㼏㼠㻌㻺㼛㼞㼕㼠㼦㻌㻭㼙㼑㼞㼕㼏㼍㻌㼒㼛㼞㻌㼙㼛㼞㼑㻌㼕㼚㼒㼛㼞㼙㼍㼠㼕㼛㼚㻚㻔㻤㻢㻢㻙㻣㻢㻢㻙㻣㻠㻤㻥㻕
This procedure is only intended for use by a qualified service professional or authorized Noritz
Service Representative. Any unauthorized use of this procedure may result in voiding the
warranty.Please contact Noritz America (866-766-7489) for additional support.
Gas
Supply
Water
Inlet
Water
Outlet
V1
V3
V4
H3
H1
Water Heater
Bucket
Flushing
Solution
Circulating
Pump
H2
Gas Supply
Valve
V1
V3
V2
V4
Continue to connect
Isolation valves**** are necessary
for flushing the Heat Exchanger.
Water Outlet
Water Inlet
V2
If a submersible pump is used,
then only 2 hoses will be needed (H1 and H3).
