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*** Isolation valves may be purchased as an accessory from
.
They allow for full diagnostic testing and easy flushing of the system
Procedure for Flushing the Heat Exchanger
If the alarm code “C1#*” is flashing on the Remote Controller, it means there is Scale Build-up in
the Heat Exchanger. To prevent damage to the Heat Exchanger from Scale Build-up, 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 alarm code “C1#*”, the Heat Exchanger must be flushed.
If the alarm code “C *” is displayed and flashing on the Remote Controller, please contact Noritz
America (866-766-7489).
* Warning indication,
= 1~9
** 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”.
The preparation of the flushing system
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 “Calcium, Lime and Rust Removal Product” and 1 gallon water into the bucket.
Noritz recommends
“Calcium, Lime and Rust Removal Product” 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.
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).
