Navien tankless water heater error codes [Reasons and Fixes]

Are you experiencing error codes on your Navien tankless water heater? Don’t worry! This comprehensive guide will help you understand the reasons behind Navien error codes and provide you with the necessary fixes to get your tankless water heater up and running smoothly again. From common error codes like E001 and E598 to more complex ones, we’ve got you covered. Don’t let error codes disrupt your hot water supply. Explore our article for valuable insights and practical solutions to keep your Navien tankless water heater functioning flawlessly with our expert advice.

Below, we provide a comprehensive Navien tankless water heater error code list that includes detailed descriptions of each error, the possible causes behind them, and steps to resolve them. We understand the importance of identifying the cause of the error and finding effective solutions which can save time and money of the users. In addition, if any components are damaged and require replacement, we will provide you with the necessary information regarding part replacement.

Navien Tankless Error Codes Complete guide and Troubleshooting

Navien E001 Error Code (Overheating Heat Exchanger):

Navien Error Code E001 typically occurs when the heat exchanger in your Navien Combi-Boiler becomes overheated. This can be caused by two main factors: a malfunctioning internal pump or too much air in the recirculation pump. Identifying the root cause of the error is crucial in order to apply the correct solution and restore the proper functioning of your Navien unit.

How to Fix Navien Error Code E001:

1. Check the Functionality of the Recirculation Pump: Before proceeding with any repairs or replacements, it’s important to verify whether the recirculation pump is functioning properly or not. Follow these steps:
   • Press the Back button on your Navien unit to reset it, ensuring there is no hot water demand.
   • Take note of the standby system pressure displayed on the front panel.
   • During normal water heater operation, the display alternates between the ‘S’ value (supply temperature) and the ‘P’ value (pressure).
   • Run hot water and observe the pressure after turning on the internal pump.
   • If the pressure fails to rise to 5 to 7 PSI (approximately), it suggests a faulty recirculation pump.
2. Replace the Recirculation Pump: If you have determined that the recirculation pump is the cause of the E001 error code, it is advisable to seek the assistance of a certified plumber or Navien technician for professional pump replacement. They have the expertise and knowledge to handle the replacement process correctly.
3. Purge the Air from the Recirculation Pump: To eliminate excessive air in the recirculation pump, follow these steps:
   • Locate the front panel of your Navien unit and remove it to access the recirculation pump.
   • Identify the air bleeder valve on the pump.
   • Carefully release the valve’s cap to allow the air to escape from the system, purging the air from the pump.
   • Once all the air is removed, replace the cap securely.

Error code E002 ( Low water pressure):

Navien Error Code E002 indicates a low water pressure fault in your Navien system. When this error occurs, you need to wait until the water supplement is terminated. The reset process is automatic and will take place once the water pressure returns to normal. It is important to ensure that there are no issues with the water supply and that the water pressure meets the requirements for the Navien system to function properly. Once the water pressure stabilizes, the system will reset itself automatically, resolving the E002 error code.

• For next one there is a dedicated article where we explained about this error and its solutions in detail please check it here: How to fix Navien Ignition failure error easily.

Error code E004 (False flame error):

The error code E004 on a Navien Tankless Water Heater indicates a false flame detection. This error message is displayed when the unit fails to detect a flame when it is expected to be present. To troubleshoot and resolve the E004 error, follow these steps:

1. Ensure Ground Wire Connection: Check that the ground wire of the unit is properly connected. A loose or disconnected ground wire can interfere with the flame detection system. Securely connect the ground wire to its designated terminal.
2. Check Igniter for Spark: Inspect the igniter to ensure it is producing a spark. A faulty or malfunctioning igniter can prevent the flame from igniting. If you do not see a spark or suspect that the igniter is not functioning correctly, it may need to be replaced.

By ensuring the ground wire is connected and checking the igniter for spark, you can address the false flame detection issue associated with the E004 error code on your Navien Tankless Water Heater. If the problem persists, it is advisable to consult a professional technician for further diagnosis and assistance.

Error code E010 (Abnormal Air Pressure):

The error code E010 on a Navien Tankless Water Heater indicates an abnormal air pressure. This error message is displayed when there is an issue with the air pressure in the unit. To troubleshoot and resolve the E010 error, follow these steps:

1. Check the Vent Pipe for Obstructions: Inspect the vent pipe connected to the water heater for any obstructions or blockages. Debris, dirt, or other objects in the vent pipe can disrupt the air pressure and cause the error code to appear. Clear any obstructions found in the vent pipe to restore proper air flow.
2. Check and Clean the Air Filter: The air filter in the Navien Tankless Water Heater plays a crucial role in maintaining proper air pressure. A dirty or clogged air filter can lead to abnormal air pressure and trigger the E010 error code. Remove the air filter and clean it thoroughly. If the filter is damaged or excessively dirty, consider replacing it with a new one.

Navien Error Code 012 (Flame Loss):

The error code E012 on a Navien Tankless Water Heater indicates a flame loss. This error message is displayed when the unit fails to detect a flame during operation. To troubleshoot and resolve the E012 error, follow these steps:

1. Check the Main Gas Line: Ensure that the main gas line supplying the water heater is open and allowing gas flow. Make sure the gas valve is fully open and there are no issues with the gas supply. If there are any concerns or doubts, contact your gas provider to verify gas availability and pressure.
2. Check the Intake Air Pipe: Inspect the intake air pipe connected to the water heater for any blockages or restrictions. A clogged intake air pipe can disrupt the combustion process and result in a flame loss. Clear any obstructions or debris from the intake air pipe to ensure proper air flow.
3. Check the Ground Wire: Verify that the ground wire connected to the water heater is properly connected. A loose or faulty ground connection can interfere with the unit’s operation and cause a flame loss. Ensure the ground wire is securely connected and in good condition.
4. Check Power Supply: Confirm that the power supply to the water heater is stable and within the correct voltage range. Fluctuations or disruptions in the power supply can lead to flame loss. Check the electrical connections and ensure there are no issues with the power source.

Error code 016 (Overheated heat exchanger):

The error code E016 on a Navien Tankless Water Heater indicates an overheating of the heat exchanger. This error message is displayed when the heat exchanger temperature exceeds the safe operating range. To troubleshoot and resolve the E016 error, follow these steps:

1. Turn off the System: Immediately turn off the water heater system and allow it to cool down for at least 30 minutes. This will help dissipate the excess heat and prevent further damage.
2. Clean the Cold Water Inlet Filter: The cold water inlet filter may be clogged or dirty, impeding the water flow and causing the heat exchanger to overheat. Locate the cold water inlet filter and clean it thoroughly to remove any debris or sediment. Ensure the filter is clean and free from blockages.
3. Check the Automatic Flow Adjustment Valve: The automatic flow adjustment valve helps regulate the water flow through the heat exchanger. Make sure the valve is functioning properly and not stuck or restricted. Clean or repair the valve as necessary to ensure smooth water flow.
4. Flush the Heat Exchanger: Over time, mineral deposits and scale can accumulate in the heat exchanger, reducing its efficiency and causing overheating. Flush the heat exchanger using a descaling solution recommended by the manufacturer. To do it yourself check our detailed article on Navien tankless water heater maintenance: Clean & Descale
5. Replace Damaged Components: If the cold water inlet filter, automatic flow adjustment valve, or heat exchanger are damaged beyond repair, they should be replaced. Contact a professional technician or Navien customer support to obtain the appropriate replacement parts and ensure they are installed correctly.

Error code E030(Exhaust overheat):

The error code E030 indicates an exhaust overheat condition. This error is triggered when the flue temperature surpasses 149°F or 65°C, causing the exhaust high limit switch to shut down the unit as a safety measure. To address and resolve the E030 error, follow these steps:

1. Turn off the unit for 30 minutes and then restart it.
2. Clean the inlet water filter to ensure proper water flow.
3. Check the automatic flow adjustment valve for any obstructions or malfunctions.
4. Check the heat exchanger and clean or flush it using a suitable descaling solution.

Error code E031 ( Burner Overheated):

Fault Code E031 on a Navien Water Heater indicates an overheating of the burner due to fuel residue buildup, it is a complex problem so we maynot be able to solve it usless we are a professional. So, In this case, it is recommended to contact Navien customer support for assistance. They will be able to provide further guidance and help resolve the issue effectively.

Error code E046 (Abnormality in limit control):

Error Code E046 on a Navien hot Water Heater indicates an abnormality in the limit control, also known as a high temperature limit control switch. This safety feature shuts off the unit when the water temperature exceeds 197.6°F in the heat exchanger.

The fault can be caused due to the detached or broken wires connected to the high limit control switch or when the resistance of the switch goes out of range.

To fix the issue, start by visually inspecting the wiring of the high limit switch. If any wires are damaged, repair or replace them as necessary.

Next, check the resistance of the high limit switch using a multimeter. If the reading is below 1.0 Ohm, it indicates a faulty limit control. In this case, the best solution is to replace the limit control switch.

Error code E047 (Abnormality in exhaust thermostat):

Error Code E047 on a Navien Tankless Water Heater indicates an abnormality in the exhaust thermostat. The exhaust thermostat is responsible for regulating the temperature of the exhaust gases.

Check the wiring of the thermostat, if possible test the thermostat resistance using multimeter If you notice any issue with thermostat try to replace it or contact Navien technical support.

Error code E060 (Abnormality in Dual venturi limit switch):

Error Code E060 on a Navien water heater indicates an abnormality in the dual venturi. The dual venturi is a crucial component responsible for regulating the flow of air and gas in the water heater.

There are a few potential reasons for the E060 error code:

1. Damaged or disconnected wiring: Visually inspect the wiring of the dual venturi and ensure there are no cracks or loose connections. If any issues are found, fix the wiring accordingly.
2. Faulty dual venturi: Test the dual venturi by running the water heater in dual venturi test mode. Observe if the dual venturi opens and closes repeatedly. If it does, this indicates a malfunction, and the dual venturi needs to be replaced.
3. Defective controller: If the dual venturi does not open and close continuously, the issue may lie with the controller. In this case, replacing the controller should resolve the E060 error code.

Error code E109 (Abnormal operation: fan motor)

Error Code E060 on a Navien unit indicates an abnormal operation of the fan motor. When this error message appears, it suggests that there are issues with the fan motor, which can be attributed to several factors:

1. Lack of power to the fan: Ensure that the fan motor is receiving the necessary electrical power. Check the voltage on the fan wiring connection (black and yellow wires) to confirm if power is being supplied.
2. Wet fan connector: Inspect the fan connector to check for any moisture. If the connector is wet, turn off the unit and dry the fan connector thoroughly before retesting the system.
3. Damaged wire connection: Ensure that the wire connection between the fan motor and the PCB (Printed Circuit Board) is secure and undamaged. Any loose or damaged connections should be addressed and repaired as necessary.
4. Defective fan motor: Perform a component test to determine if the fan motor is functioning properly. Refer to the manufacturer’s guide for instructions on conducting this test. If the fan motor is found to be faulty, it will need to be replaced.

Error code E110 ( Abnormal Air pressure)

Error E110 indicates an abnormal air pressure issue. There is a dedicated article where we explained about this error and its solutions in detail please check it here: Navien tankless water heater E110 code: Easy steps to fix

Error code E351 (Abnormal Auto Feeder Valve)

Error Code E110 on a Navien water heater indicates an abnormal auto feeder valve. When this error occurs, it suggests that there are issues related to the auto feeder valve, which can be resolved by following these steps:

1. Inspect for leaks: Begin by thoroughly inspecting your entire tankless water heater for any signs of leakage. If you discover any leaks, address them promptly by fixing the source of the leak. This will help ensure proper functioning of the unit. To fix leaking refer our article: Tankless water heater leaking? find and stop the leak
2. Check the auto feeder valve: Verify that the auto feeder valve is operating normally. If it is not functioning properly, it may need to be replaced. It is recommended to enlist the assistance of a certified plumber to handle this task, as they have the expertise to ensure the replacement is done correctly.
3. Open the DHW cold water valve: Ensure that the domestic hot water (DHW) cold water valve is fully open. Check the connections and the water pressure sensor associated with the valve to ensure they are functioning as intended.
4. Address low water pressure: If the error persists, it is important to investigate and address any issues related to low water pressure. This can involve adjusting the water pressure or identifying and resolving the underlying cause of the low water pressure problem.

Error code E407, E421, E432 (Hot water outlet: Thermistor open or short circuit)

Error Code E407 on a Navien water heater signifies a fault related to the hot water outlet thermistor. This error occurs when the thermistor is either open or experiencing a short circuit. To resolve this issue, follow these steps:

1. Check the thermistor: Begin by inspecting the hot water outlet thermistor. Ensure that it is securely in place and not damaged. Look for any signs of wear, such as frayed wires or loose connections.
2. Confirm thermistor connection: Verify that the thermistor is properly connected to the designated terminals on the water heater. Make sure the connection is secure and there are no loose or disconnected wires.
3. Replace the thermistor: If the thermistor is found to be faulty or damaged, it needs to be replaced. Obtain a compatible replacement thermistor and carefully install it according to the manufacturer’s instructions. Take note of the specific model and specifications of the thermistor to ensure proper replacement.

Error code E421 or E432 (Cold water inlet: Thermistor open or short circuit)

Error Code E421 or E432 on a Navien water heater indicate faults with the cold water inlet 1 or 2 thermistors respectively. These errors occur when the thermistors experience an open circuit or a short circuit. To address these issues:

1. Check the thermistors: Inspect both the cold water inlet 1 and cold water inlet 2 thermistors. Ensure they are in good condition without any visible damage. Look for frayed wires or loose connections.
2. Confirm thermistor connection: Verify that the thermistors are securely connected to their respective terminals on the water heater. Check for any loose or disconnected wires and ensure proper alignment.
3. Replace the thermistors: If the thermistors are found to be faulty or damaged, they should be replaced. Obtain suitable replacement thermistors that match the specifications of your water heater model. Install the new thermistors carefully, following the manufacturer’s instructions.

Error code E434 (Abnormal water adjustment valve)

Navien tankless water heater Error Code E434 indicates an abnormal operation of the water adjustment valve. To address this issue, follow these steps:

1. Check the adjustment valve: Inspect the water adjustment valve to ensure it is functioning correctly. Look for any signs of damage, such as leaks or blockages. Ensure the valve moves freely and operates smoothly.
2. Check the adjustment valve connection: Verify that the adjustment valve is properly connected to the water heater. Check for loose or disconnected wires, as well as any corrosion or damage to the connections.
3. Replace the valve if needed: If the adjustment valve is found to be faulty or damaged beyond repair, it will need to be replaced. Contact the manufacturer or a qualified technician to obtain a suitable replacement valve. Install the new valve following the manufacturer’s instructions.

Error code E438 ( Abnoramal Recirculation pump operation)

If you encounter Error Code E438 on your Navien Tankless Water Heater, it indicates an abnormal operation of the recirculation pump. This error can be caused by issues such as faulty check valves, a defective flow sensor, or a damaged pump. Follow these steps to resolve the problem:

1. External: Ensure that all water supply and return lines are open. Check for any obstructions or restrictions in the lines and clear them if necessary. Proper water flow is essential for the recirculation pump to function correctly.
2. Internal: Check the direction of the 2-way valve. Verify that the valve is positioned correctly to allow proper water flow through the recirculation system. Adjust the valve if needed according to the manufacturer’s instructions.
3. Check the condition of the flow sensor: If there is any scale or debris buildup on the sensor, clean it thoroughly. This can help restore proper functionality and accurate readings.
4. Inspect the recirculation pump itself: If the pump is damaged or not functioning properly, it will need to be replaced. Contact a professional technician or Navien customer support for assistance in identifying and replacing the faulty pump.

Error code E515 (Abnormality in PCB)

If you come across Error Code E515 or E515-09 on your Navien system, it indicates an abnormality with the PCB (Printed Circuit Board). The following factors may be responsible for this error:

1. Visually inspect PCB and its connections: Take a close look at the PCB and its connections to other components. Look for any loose or damaged connections, as they can contribute to the abnormal operation.
2. Power supply issue: Check the power supply to ensure it is stable and providing the correct voltage to the PCB. Fluctuations or inadequate power supply can disrupt the PCB’s functionality.
3. Power supply grounding noise: Verify that there is no electrical noise or interference in the power supply grounding. Excessive noise can affect the PCB’s performance and lead to an E515 error.
4. Bad PCB: The PCB itself may be faulty or malfunctioning, causing the error code to appear.

Error code E517 (Abnormal DIP switch setting)

If your Navien system displays Error Code E517, it indicates an abnormal operation related to the DIP switch settings. This error typically occurs when there is an issue with the configuration of the DIP switches.

The DIP switches are small switches located on both the front panel and the PCB (Printed Circuit Board) of the unit. These switches control various settings and parameters of the system. An incorrect or misconfigured DIP switch setting can trigger the E517 error.

To resolve this issue, follow these steps:

1. Confirm all DIP switches: Check all the DIP switches on the front panel and PCB to ensure they are properly set according to the recommended configuration for your specific Navien model. Take note of the desired configuration and compare it to the current switch positions.
2. If you find any misconfigured or incorrectly set DIP switches, adjust them to the appropriate positions as specified in the system’s documentation or user manual. Once you have made the necessary changes, reset the unit and check if the E517 error code is resolved.

Navien Error 598-00 (Abnormal RTC)

If your Navien tankless water heater displays the error code 598-00, it indicates an issue with the Real-Time Clock. To resolve this error, first check the wiring near the PCB and inspect if something is not usual, if PCB and its connections looks good, you can try factory resetting the unit by following these steps:

1. Press and hold the “M” and back arrow buttons together for 5 seconds to access the installation and service menu.
2. Use the up/down arrows to navigate and find the line number for the factory reset option.
3. Once the factory reset option is highlighted, press the OK button to proceed.
4. The screen will turn green and count up to 100% as the factory reset process completes.
5. After the reset, the water heater will enter a standard 1st-time start-up wizard.
6. Set the date and time, select the appropriate elevation (e.g., 0-2000 feet for Ohio), and accept other default options.
7. If prompted for a 4-digit password, use the default password provided by your installer (e.g., 1234).

If the above steps do not resolve the E598-00 error, it is recommended to contact Navien customer support. They will be able to assist you further by checking the PCB (printed circuit board), and if it is found to be faulty, they will arrange for its replacement.

Error code E760 (Flushing/Service alarm)

Error Code E760 on your Navien system signifies a flushing/service alarm. It indicates that your system requires servicing and flushing. Regular maintenance, including the removal of scale and lime buildup, is essential to extend the lifespan of your tankless water heater and ensure its continued high efficiency.

Conclusion:

Navien tankless water heaters are sophisticated systems that may encounter errors and electronic issues. Understanding the error codes and their causes is crucial for diagnosing and resolving problems with your Navien unit. By following the appropriate fixes and solutions, you can effectively troubleshoot and rectify these errors, ensuring your tankless water heater operates smoothly and efficiently.