Rinnai Error Codes

Error Code 02: No burner operation during freeze protection mode.

Call a plumber.

Error Code 03: Power interruption during bath fill

Turn off all hot water faucets/taps. Press On/Off button twice. Turn hot water back on and test. You may have to try this a couple times to reset the system.

Error Code 10: Exhaust or air supply blocked

There are several things you can do before calling a plumber. Try the following:

Check venting material. Is it Rinnai-approved? (See Rinnia-approved venting materials here.) If not, replace venting material or have a plumber replace it.
Look for blockages in both the flue inlet or exhaust.
Are the venting components properly connected?
Check the condensation collar. Is it loose or improperly installed?
Are the dip switches set correctly?
Is the fan rotating properly, or is something blocking it?

If the error code still shows, call a plumber.

Error Code 11: Ignition problems

Because this has to do with gas and gas lines, most people will need to call a plumber to handle this. However, these are steps the plumber will take (and you could carefully try some of these yourself):

Is the gas on? Check at the water heater, gas meter or cylinder.
Is the gas type and pressure correct?
Is the gas line, meter and/or regulator sized properly?
Is the air in the gas line? Have a plumber bleed the air from the lines.
Are the dip switches set?
Is the appliance grounded?
Disconnect EZConnectTM or MSA controls to see if you can isolate the problem.
Does the igniter work? Is it operational or do you need to replace the igniter? Check the wiring harness and see if it’s the igniter or the harness.
Examine the gas solenoid valves. Any open or short circuits?
Remove the burner cover and examine the burners to see if they are one, properly sealed, and two, if the burner surface has condensation or debris on it.

If you are not familiar with these parts and with both wiring and gas, you should hire a plumber to deal with a Rinnai error code 11.

Error Code 12: Flame failure

Because this has to do with gas and gas lines, most people will need to call a plumber to handle this. However, you could carefully try some of the steps a plumber will take. Use the checklist for Rinnai error code 11 (above), and if those steps don’t fix the problem, try the following:

Check power supply. Any loose connections?
What is the voltage? Any voltage drops?
Is the flame rod wire connected? Any problems with carbon build up on the flame rod?
Check for DC shorts at components.

If you are not familiar with these parts and with both wiring and gas, you should hire a plumber to deal with a Rinnai error code 12.

Error Code 14: Thermal fuse

Something is wrong with the thermal fuse. You may be able to fix it by trying the following:

Check for air flow restrictions.
Is water flow in the circulating system low? This can cause problems related to short-cycling.
Check dip switches.
Anything gunking up the combustion chamber? What about the exhaust pipe? Obstructions can cause problems with thermal fuse function.
How does the heat exchanger look? Any cracking or separations? Hot spots? Hot spots indicate scale build up.
Flush the heat exchanger following the instructions on the owner’s manual.
Check the resistance of the safety circuit.

Error Code 16: Over temperature warming

This problem usually is caused by a restriction of airflow. Check for clogs or obstructions in the following:

Combustion chamber
Exhaust piping
Heat exchanger

You will also want to check for restrictions in air flow around unit and vent terminal and for low water flow in a circulating system causing short-cycling. Once you clear the obstructions and improve airflow and water flow, the problem should resolve itself. If it does not, call a plumber.

Error Code 32: Outgoing Water Temperature Sensor Fault

This one is simple: carefully examine the sensor. Look for damage and scale build up. You probably have to replace the sensor if cleaning it doesn’t help.

Error Code 33: Heat Exchanger Outgoing Temperature Sensor Fault

Similar to above. Carefully examine the sensor. Look for damage and scale build up and make sure the fan blade is tight on motor shaft and is undamaged. You probably have to replace the sensor if cleaning it doesn’t help.

Error Code 34: Combustion Air Temperature Sensor Fault

Same as above. Carefully examine the sensor and wiring. Look for damage and scale build up. You probably have to replace the sensor if cleaning it doesn’t help.

Error Code 52: Modulating Solenoid Valve Signal Abnormal

You probably need to replace the solenoid valve. First:

Check modulating gas solenoid valve wiring harness for loose or damaged terminals.
Measure resistance of valve coil.
You may be able to resolve the problem by tightening loose terminals.

Error Code 61: Combustion Fan Failure

Examine the combustion fan to see:

Can the fan turn freely?
Any problems with the wiring harness? Maybe it has been damaged or has loose connections?
Is there a problem with the motor winding resistance?

Error Code 65: Water Flow Control Fault

You definitely need to call a plumber for this one. The water flow control valve has failed to close during the bath fill function. Immediately turn off the water and discontinue the bath fill function. Then call a plumber.

Error Code 71: Solenoid Valve Circuit Fault

You probably need to replace the solenoid valve. First:

Check wiring harness to all solenoids.
Measure resistance of each solenoid valve coil.

Error Code 72: Flame Sensing Device Fault

Before you call a plumber, you can try the following:

Check to see if the flame rod is touching flame when the unit fires.
Examine the wiring to flame rod for damage.
Clean the flame rod with sandpaper.
Examine inside the burner chamber for debris or gunk that might be blocking the flame at the flame rod.
Replace flame rod.

Error Code 00 or “LC”: Scale build up in heat exchanger.

Call a plumber and have them flush the heat exchanger or replace the heat exchanger.

Note: A lot of customers ignore this code because it still allows the tankless water heater to continue running. You will see the display alternates between the LC code and the temperature setting. Make sure you get the heat exchanger serviced and don’t ignore this code just because it allows you to still run the unit or you may have more serious problems down the line.

Navien Error Codes

Navien Error Code E001 Water is boiling inside the heat exchanger Clean the inlet water filter
Check the heat exchanger; flush it with a cleaning solution

Navien Error Code E002 Low water pressure Wait until the water supplement is terminated.

Navien Error Code E003 Ignition failure Check if the main gas supply valve is open
Check the igniter for spark

Navien Error Code E004 False flame detection Check if the main gas supply valve is open
Check the igniter for spark

Navien Error Code E005 Heating supply outlet: Thermistor–open Ensure the ground wire is connected
Check the igniter for spark

Navien Error Code E006 Heating supply outlet: Thermistor–short Check the thermistor
Check for loose connection
Replace the thermistor

Navien Error Code E007 Hot water outlet: Thermistor–open Check the thermistor
Check for loose connection
Replace the thermistor

Navien Error Code E008 Hot water outlet: Thermistor–short Check the thermistor
Look for short or water in connection
Replace the thermistor

Navien Error Code E09 Abnormal fan motor activity Check and clean the air filter
Check and clean the fan motor
Check the tower on board for loose connection

Navien Error Code E010 Abnormal air pressure Check the vent and fresh air pipe for obstructions
Check and clean the air filter
Check hoses and condensate drain

Navien Error Code E011 High water pressure Check the water pressure sensor Automatic

Navien Error Code E012 Flame loss Check the main gas line (valve open?)
Check the intake air pipe
Check ground wire
Check power supply
Clean flame rod

Navien Error Code E013 Abnormal pump Check the pump
Remove air from the pipe

Navien Error Code E015 Abnormal control board Check power supply
Check the Emergency Switch

Navien Error Code E016 Overheating of heat exchanger Turn OFF the system for at least 30 minutes then restart
Clean the inlet water filter
Check the heat exchanger; flush with a
cleaning solution

Navien Error Code E018 Heating return inlet: Thermistor–open Check the Thermistor
Check for loose connection
Replace the Thermistor

Navien Error Code E019 Heating return inlet: Thermistor–short Check the Thermistor
Check for short or water in connection
Replace the Thermistor

Navien Error Code E021 Cold water inlet: Thermistor–open Check the Thermistor
Check for loose connection
Replace the Thermistor

Navien Error Code E022 Cold water inlet: Thermistor–short Check the Thermistor
Check for short or water in connection
Replace the Thermistor

Navien Error Code E027 Abnormal activity of the air pressure sensor Check the vent pipe for obstructions
Check and clean the air filter

Navien Error Code E028 Water leak pipeline Check pipeline.

Navien Error Code E030 Exhaust Overheat: exhaust high limit
the switch shuts down the unit when the flue
temperature exceeds 149°F (65°C) Clean the inlet water filter
Check the heat exchanger; flush it with a cleaning solution

Navien Error Code E035 Abnormal activity of the gas pressure sensor Measure gas pressure drop
Check hose connection
Replace GPS.

Navien Error Code E036 Communication failure Contact Navien tech. dept.

Navien Error Code E039 Abnormal the Water Flow Sensor Check the water flow sensor.

Navien Error Code E040 Outdoor: Thermistor–short Check the Thermistor
Replace the Thermistor

Navien Error Code E048 Abnormal LPG Gas Pressure Check the LPG Gas.
Fill the LPG Gas.