If you’re still figuring out the quirks of your Rinnai system from Part I, you’re in the right place. In this next part, we’ll break down more error codes and help you solve issues with your hot water. Whether you’re a DIY trouble-shooter or need expert help in Adelaide, ABA Plumbing & Gas is here for you.

Rinnai hot water systems troubleshooting guide

Error Code 33: Heat Exchanger Outgoing Temperature Sensor Fault
Call ABA Plumbing & Gas for troubleshooting.

Error Code 34: Combustion Air Temperature Sensor Fault
Call ABA Plumbing & Gas for troubleshooting.

Error Code 38: Exhaust Thermistor CO Sensor
Call ABA Plumbing & Gas for troubleshooting.
Check sensor wiring for damage.
Measure the resistance of the sensor.
Clean sensor of scale build-up.
Replace sensor.

Error Code 41: Outside Temperature Thermistor Freeze Protection Sensor
Call ABA Plumbing & Gas for troubleshooting.

Error Code 51: Inlet Water Temperature Thermistor (Sensor)
Call ABA Plumbing & Gas for troubleshooting.
Check sensor wiring for damage.
Measure the resistance of the sensor.
Clean the sensor of scale build-up.

Error Code 52: Inlet Water Temperature Thermistor (Sensor)
Call ABA Plumbing & Gas for troubleshooting.
Check for blockage of the main servo.
Check the operation of the main servo.
The main servo may need to be replaced.

Error Code 54: High Exhaust Gas Temperature
Call ABA Plumbing & Gas for troubleshooting.
Ensure Heat Exchanger fins are clean and not blocked.
Confirm inlet water temperature is not too high.
Clear the diagnostic code by resetting the main power supply to the water heater.

Error Code 57: Burner Overheat Bi-Metal Switch
Call ABA Plumbing & Gas for troubleshooting.

Error Code 58: Secondary Heat Exchanger Sensor
Call ABA Plumbing & Gas for troubleshooting.
Scale build-up in the secondary heat exchanger needs flushing.

Error Code 61: Combustion Fan Motor Failure
Call ABA Plumbing & Gas for troubleshooting.
Ensure the fan turns freely.
Check wiring harness to the motor for damage.
Measure the resistance of the motor winding.

Error Code 63: Recirculation Low Flow Circulation Flow Rate dropped below 1.3 GPM
Call ABA Plumbing & Gas for troubleshooting.
Ensure the bypass plug is removed, and the bypass filter is installed.
Ensure both the inlet water filter and bypass filter are clean.
Ensure Parameter settings are correctly set for recirculation mode.
Ensure Pump supply voltage.
Ensure air is removed from the recirculation line.

Error Code 65: Water Flow Control Fault
Call ABA Plumbing & Gas for troubleshooting.
The water flow control valve has failed to close during the bath fill function.

Error Code 70: PC Board
Call ABA Plumbing & Gas for troubleshooting.
Check PC board DIP switches for the correct position.
Check the connection harness at the connection on the PC board.

Error Code 71: Solenoid Valve Circuit Fault
Call ABA Plumbing & Gas for troubleshooting.
Replace the PC board.

Error Code 72: Flame Sensing Device Fault
Call ABA Plumbing & Gas for troubleshooting.
Ensure the flame rod is touching the flame.
Check wiring to the flame rod for damage.
Remove the flame rod and check for carbon build-up; clean with sandpaper.
Check inside the burner chamber for any foreign material blocking flame at the flame rod.
Measure the micro amp output of the sensor circuit with the flame present.
Replace the flame rod.

Error Code 73: Flame Sensing Device Fault
Call ABA Plumbing & Gas for troubleshooting.
Check sensor wiring and PC board for damage.
Replace sensor.

Error Code 79: Flame Sensing Device Fault
Call ABA Plumbing & Gas for troubleshooting.
Water has been detected at the bottom of the unit. Turn off the water supply.
Check all plumbing internally for leakage.

Error Code LC, LC10, LC1, LC2, LC2 00: Scale Build-up in Heat Exchanger
Call ABA Plumbing & Gas for troubleshooting.
Flush heat exchanger. Refer to the instructions in the manual.
Replace the heat exchanger.
LC0-LC9 indicates scale build-up; flush heat exchanger as per manual.
To operate temporarily, push the On/Off button on the temperature controller 5 times.
For further troubleshooting, call or contact ABA Plumbing & Gas.

Error Code SS: (SS) Service Soon (Flush Heat Exchanger)
For scheduled service, call ABA Plumbing & Gas.
Flush heat exchanger as per manual to prevent damage.
To reset the SS code, push the On/Off button on the temperature controller 5 times in 5 seconds.

Error Code FF: Maintenance Has Been Performed
Indicates licensed professional maintenance or issue correction.
No action required.

Connect with Your Local Rinnai Hot Water Experts at ABA Plumbing & Gas!

If you’re facing issues with your Rinnai hot water unit, have questions about error codes, or need emergency plumbing and hot water repairs Adelaide services, reach out to us. Our dedicated team of 24/7 emergency hot water plumbers are ready to provide swift solutions with a quick turnaround.

For additional insights into Rinnai hot water systems and our services, explore the following resources: https://www.abaplumbing.com.au/hotwater-repairs-adelaide/rinnai-hot-water/