Every tankless water heater will eventually prank you with an unexpected diagnostic code. Unfortunately, it usually happens at a bad moment. Navien tankless water heaters are the same way.
This error code, however, can assist you in figuring out what is wrong with your tankless water heater so that you can take the necessary action, although it could be a more pleasant experience.
There will probably be an audible “beeping” alert when an error code occurs. If you don’t have hot water, your tankless water heater may have reached capacity or has at least one problem code.
The Navien tankless water heater problem codes, their significance, troubleshooting, and other topics will be covered in this tutorial. Therefore, let’s look.
Overheating Heat Exchanger: Error Code E001
A heat exchanger that is too hot causes the Navien error code E001. You should clean the filter and flush the heat exchanger to resolve Navien error number E001. Ensure the water is correctly circulated and the pump’s flow rate and PCB voltage are within specifications.
For tankless water heater upkeep, we provide a how-to manual. How to do tankless water heater flushing and other maintenance is described in Easy Maintenance Tips for Tankless Water Heaters with Photos.
Low Pressure on the Heating Side: Error Code E002
Error code for Navien E002 indicates that the heating side is under low pressure. Low water pressure may result in the Navien error number E002. Thus, you must make sure the appliance gets adequate water. The device might also need to be restarted to resolve this error code.
Failure of the ignition: error code E003
The error code for Navien E003 denotes a problem with the unit’s ignition. If your Navien shows the error number E003, ensure the igniter is sparking, the device is powered up, the ground wire is connected, and the gas supply is on and operational.
If required, clean the igniter electrode or the PCB.
This can also happen when there is a power outage. Consider looking into a battery backup power supply for your tankless water heater if you are in a region that frequently has blackouts or power outages.
False Flame Detection: Error Code E004
The Navien error number E004 signals that the device picks up a fake flame. Verify that the ground wire is connected correctly and is not loose to fix Navien error number E004. Additionally, make sure the igniter is creating a spark.
High Pressure on Heating Side: Error Code E011
The error code for Navien E011 indicates that the heating side is under intense pressure. By turning off the appliance, emptying the water to release the tension, and then turning it back on, you can resolve this problem code. Check the sensor’s condition if the issue continues. Replace the sensor as needed.
Flame Loss: Error Code E012
E012 on a Navien error code indicates a flame loss. Check if the main gas valve is open and the gas pressure is within specifications to troubleshoot and resolve Navien error code E012. Additionally, examine the wiring at the heat exchanger, the power supply, the ground wire, and the intake air filter.
The anti-short cycle time may also need to be checked and adjusted since, in certain cases, it might result in an error code E012.
Overheating Heat Exchanger: Error Code E016
The error code for Navien E016 indicates an overheated heat exchanger. Navien error code E016 may be fixed and troubleshot by turning the device off for 30 seconds and then turning it back on. Flushing the heat exchanger and inspecting and cleaning the cold water filter and strainer. Examine the PCB, the 3-way valve, and the high-limit switch.
Exceptional Exhaust Temperature: Error Code E030
The error code for Navien E030 is brought on by an exhaust that is too hot. Turn the device off for 30 seconds, then turn it back on to diagnose and resolve Navien error number E030. Examine the heat exchanger and the filter. If necessary, flush the heat exchanger and clean the filter.
The device will stop operating if the exhaust temperature rises beyond 230°F (110 °C) for over 10 seconds.
Heat Exchanger Error: Error Code E046
The heat exchanger thermistor has a short, indicated by the Navien error number E046. Examine the state of the wiring at the heat exchanger thermistor to resolve Navien error code E046. Ensure that the wiring is in good shape and that there are no weak connections.
Limit control may also cause the Navien error code E046, which is best to contact a qualified contractor for more assistance.
Exhaust Thermistor Error: Error Code E047
The error code for Navien E047 is a sign that something is wrong with how the exhaust thermistor is operating. The connection and wiring at the exhaust thermistor must be checked to resolve Navien error code E047, which an open or shorted exhaust thermistor may bring.
Dual Venturi Limit Switch Error: Error Code E060
The error code for Navien E060 denotes a twin venturi limit switch issue. You should examine the dual venturi connection if your Navien shows the error number E060. In rare cases, replacing the double venturi entirely may be necessary to resolve this problem code.
Incorrect Fan Motor Activity: Error Code E109
A problem with the fan motor is indicated by the Navien error number E109. Examine and clean the fan motor and air intake filter to resolve Navien error code E109. If the error code still appears, check the PCB voltage; replace the fan if it is within specifications.
Exhaust Blockage Error: E110
The error code for Navien E110 indicates an obstruction in the exhaust. E110 checks that nothing is blocking or obstructing the exhaust pipe and that it is clear to resolve the Navien problem number. Additionally, evaluate the intake air filter’s state and clean it as necessary.
Additionally, the condensate obstruction may be the source of this error number. You should replace the air pressure sensor if the error code still appears even after you reset the device.
APS Error (Open, Short, Initial Value, or No Response): Error Code E127
Error code for Navien A malfunction with the air pressure sensor (APS) is indicated by the code E127. Code of error An open or shorted APS may be the source of E127. Turn the device off, then check the APS’s health. After a reset, if the issue code still appears, you should replace the APS.
H/E Outlet Thermistor Open or Short Error: Code Error E205
The error code for Navien E205 denotes a fault with the functionality of the heating supply thermistor. An open or shorted thermistor can bring on the Navien error code E205. Examine the condition of the pump wire connections and the heating supply thermistor to resolve this error code.
Thermistor in H/E Inlet Open or brief: Error Code E218
An issue with the heating return thermistor’s functionality is indicated by the Navien error code E218. An open or short thermistor may bring on the Navien error number E218. Examine the condition of the pump wire connections and the heating return thermistor to resolve this problem code.
Low water pressure error: Error code E302
The water pressure is too low when the Navien error code E302 is present. Check the water feeder valve, water pressure, and water pressure relief valve if your Navien is flashing the error number E302. If necessary, swap out any damaged components.
Error with High Water Pressure: Error Code E352
High water pressure is indicated by the Navien trouble number E352. If your Navien shows the error number E352, you must ensure that the water pressure is within safe limits and that the feeder and the pressure release valve are operating as intended.
Water pressure sensor error: Error code E353
Water pressure sensor issues are indicated by the Navien error number E353. An open or shorted sensor may bring on Navien error code E353. Verify that the wiring and water pressure sensor are in excellent working order and that there are no loose connections. Change the sensor if necessary.
Hot Water Outlet 1: Thermistor Open or Short: Error Code E407
The code E407 indicates an error code for Navien, An issue with the hot water outlet thermistor. An open or shorted sensor brings on the Navien error code E407. Examine the wiring and state of the thermistor to find the problem. The thermistor should be changed if necessary.
Cold Water Inlet 1: Thermistor Open or Short: Error Code E421
The cold water inlet one thermistor is having an issue, according to Navien error number E421. An open or shorted sensor brings on the Navien error code E421. Examine the wiring and state of the thermistor to find the problem. Replace the cold water inlet thermistor if required.
Cold Water Inlet 2: Thermistor Open or Short: Error Code E432
Error code for Navien, An issue with the cold water inlet two thermistors is indicated by the code E432. An open or shorted sensor brings on the Navien error code E432. Examine the wiring and state of the thermistor to find the problem. The thermistor should be changed if necessary.
Abnormality in the water adjustment valve: Error code E434
The error code for Navien E434 indicates that the water adjustment valve is malfunctioning. An open or shortened water adjustment valve may be the root of the Navien error code E434. Turn off the tankless water heater and check the wiring and condition of the valve. If required, make a service request.
Circulation Pump Abnormality: Error Code E438
E438 on a Navien error code indicates a circulation pump issue. Check the water supply, circulators, flow sensor, and pump to resolve this problem code. You might have to change the pump, flow sensor, or PCB if there is an error code E438.
Abnormal Flow Sensor: Error Code E439
Error code for Navien, An issue with the flow sensor is indicated by the code E439. A malfunctioning flow sensor, PCB, or absence of cold water supply are all potential causes of error code E439.
Check whether there is water flow while the cascade system is off to resolve this problem code. Check the flow sensor connector’s condition and clean it if there is water flow.
Hot Water Outlet 2: Thermistor Open or Short: Error Code E441
Error code for Navien A issue with the hot water outlet the code E441 indicates two thermistors. An open or shorted sensor brings on the Navien error code E441. Examine the wiring and state of the thermistor to find the problem. The thermistor should be changed if necessary.
Abnormal Mixing Valve: Error Code E445
The error code for Navien E445 denotes a problem with the mixing valve. The common causes of the Navien error code E445 include a bad feedback sensor, a broken, opened, shorted, or blocked mixing valve, or a bad PCB. Contact a qualified technician if necessary.
External Tank Thermistor Open or Short (System Boiler Thermistor Setting Only): Error Code E480
The external tank thermistor is having trouble, often due to an open (at temperatures below 14°F) or shorted sensor. Make sure the connections on the sensor are installed properly and are dry by inspecting them. Replace the tank thermistor if necessary.
PCB error: Error code E515.
A problem with the PCB is indicated by the Navien error number E515. The PCB, PCB’s monitoring device, igniter, fan, dual venturi, and 3-way valve should all be examined in the event of an error code E515. Ensure they are in excellent shape and are correctly attached to the PCB.
DIP Switch Setting Error: Error Code E517
The Navien error code E517 denotes a dip switch issue. You must inspect the dip switches on the unit’s front panel and the PCB to diagnose and resolve Navien error number E517.1. Call a qualified technician if the issue continues despite everything appearing in the order.
Incorrect Panel Key: E593 Error
The front panel keys’ functionality is the root of Navien error code E593. To resolve Navien error number E593, you must verify that the panel’s keys function properly if they restart the device but do not change the front panel.
Partial PCB Communication Error: Error Code E594
A partial PCB communication fault or an EEPROM error are both indicated by the Navien error number E594. Examine the PCB of the device for any damage or wiring problems. To have the condition of your Navien tankless water heater assessed, get in touch with a competent contractor if the error continues, and nothing seems out of the usual.
In addition, to make sure everything is in working order, you should also examine the wiring and state of the exhaust sensor, flame rod, and pressure sensor.
Memory and Input Issues: Error Code E615
The error code for Navien E615 might signify a memory error or an input data error. Check the PCB, the exhaust sensor, the flame rod, and the pressure sensor wire after resetting the device. Check the pressure sensor’s output voltage to ensure it is within tolerance. If assistance is required, dial.
Abnormal Cascade Communication: Error Code E736
An issue with the cascade communication is indicated by the Navien error number E736. Check the ready-link cascade cable installation and cascade settings, as well as the compatibility of the PCB version. Contact a qualified technician if the issue persists after resetting the device.
Incorrect Outdoor Sensor: Error Code E740
The E740 Navien error number denotes a malfunctioning outside temperature sensor. An open or shorted sensor may bring on Navien error code E740. Ensure that the sensor’s wiring is in excellent shape and properly functioning and that the outside reset curve is set up appropriately to remedy the issue.
Flushing Alarm: Error E760
Error code for Navien A flushing service alarm is E760. This error code serves as a reminder rather than an actual error. If your Navien tankless water heater shows the trouble code E760, you must cleanse the heat exchanger.
Main Panel Communication Error: Error Code E782
A communication problem within the main panel is indicated by the Navien error code E782. Examine the state and functionality of the PCB to resolve Navien error number E782. You should hire a certified professional to examine your unit’s condition and, if necessary, replace the PCB to resolve this issue.
OT-remote Controller: Error Code E783
Navien error message E783 indicates an issue with the OT-remote controller’s functionality. Check the controller’s condition and replace it if necessary.
Abnormal Operation of the Flow Switch: Error Code E785
Navien error message E785 denotes an external flow switch’s functionality issue. Examine the flow switch and the cold water pipe for damage. Check the resistance of the thermal block and the flow switch to see if they are in the on or off state. Replace the sensor or the controller as necessary.
Device Reset Error: Error Code E787
The Navien error code E787 denotes an issue during the unit’s reset. Please turn off the device for at least 30 seconds, check that everything functions as it should, and then turn it back on. Have a technician assess the unit’s condition if the error code continues to appear.
In the normal 20-year lifespan of a tankless water heater, one of these Navien error codes will undoubtedly appear. Our buying advice will be useful, and you will bookmark it for future use.
