Rinnai Understanding Error Codes: Common Issues Including Code 12

Error Codes

The Rinnai water heater has the ability to check its own operation continuously. If a fault occurs, an error code will flash on the Display of the temperature controller. This assists with diagnosing the fault and may enable you to overcome a problem without a service call. Please identify the code displayed when inquiring about service.

Code	Fault		Remedy
03	Power interruption during		Turn off all hot water taps. Press ON/OFF twice.
	Bath Fill (Water will not flow
	when power returns).
10	Air Supply or Exhaust		Ensure Rinnai approved venting materials are being used.
	Blockage		Check that nothing is blocking the flue inlet or exhaust.
			Check all vent components for proper connections.
			Ensure vent length is within limits.
			Verify dip switches are set properly.
			Check fan for blockage.
			Burner Sensor Error (see code 31)
			Check the fins in the heat exchanger.
11	No Ignition		Check that the gas is turned on at the water heater, gas meter, or cylinder.
			Ensure gas type and pressure is correct.
			Ensure gas line, meter, and/or regulator is sized properly.
			Bleed all air from gas lines.
			Verify dip switches are set properly.
			Ensure appliance is properly grounded.
			Disconnect EZConnect™ or MSA controls to isolate the problem.
			Ensure igniter is operational.
			Check igniter wiring harness for damage.
			Check gas solenoid valves for open or short circuits.
			Remove burner cover and ensure all burners are properly seated.
			Remove burner plate and inspect burner surface for condensation or debris.
12	Flame Failure		Check that the gas is turned on at the water heater and gas meter. Check for obstructions in
			the flue outlet.
			Ensure gas line, meter, and/or regulator is sized properly.
			Ensure gas type and pressure is correct.
			Bleed all air from gas lines.
			Ensure proper Rinnai venting material was installed.
			Ensure vent length is within limits.
			Verify dip switches are set properly.
			Ensure appliance is properly grounded.
			Disconnect keypad.
			Disconnect EZConnect™ or MSA controls to isolate the problem.
			Check power supply for loose connections.
			Check power supply for proper voltage and voltage drops.
			Ensure flame rod wire is connected.
			Check flame rod for carbon build-up.
			Disconnect and reconnect all wiring harnesses on unit and PC board.
			Check for DC shorts at components.
			Check gas solenoid valves for open or short circuits.
			Remove burner plate and inspect burner surface for condensation or debris.
			Check the ground wire for the PC board.
14	Thermal Fuse		Check gas type of unit and ensure it matches gas type being used.
			Check for restrictions in air flow around unit and vent terminal.
			Check for low water flow in a circulating system causing short-cycling.
			Ensure dip switches are set to the proper position.
			Check for foreign materials in combustion chamber and/or exhaust piping.
			Check heat exchanger for cracks and/or separations.
			Check heat exchanger surface for hot spots which indicate blockage due to scale build-up.
			Refer to instructions in manual for flushing heat exchanger.
			Measure resistance of safety circuit.
			Ensure high fire and low fire manifold pressure is correct.
			Check for improper conversion of product.
12		Manual - Rinnai Condensing Water Heaters