Navien Tankless Water Heater Error Codes (2024)

Have you encountered a problem with your Navien tankless water heater? Is it displaying an error code but you don’t know what it means?

Although tankless water heaters don’t require much maintenance, they aren’t perfect and problems do occur, leaving you with no hot water. Navien is a manufacturer that provides an error code to help you, but this isn’t very useful if you don’t know what each code means.

To help you solve the problem, we have provided a breakdown of various Navien error codes in this article. We will also take a more in-depth look at some of the most common Navien tankless water heater problems.

Key Takeaways

  • Navien tankless water heaters display error codes to help identify issues.
  • Common problems include ignition failure, false flame detection, and heat exchanger overheating.
  • Most issues can be resolved by cleaning filters, checking connections, or resetting the unit.
  • For more complex issues, contact Navien technical support at 1-800-519-8794.

Table of Contents

  • Navien Tankless Error Codes Breakdown
  • Common Navien Tankless Water Heater Problems
  • How to Reset a Navien Tankless Water Heater
  • Where is the Serial Number on a Navien Water Heater?
  • FAQs

Navien Tankless Error Codes Breakdown

Tankless water heater systems require several essential parts to work properly, so you are bound to encounter problems at some point. Each error code your tankless heater might display corresponds to a specific issue with the boiler, so read on for a comprehensive list. It should explain most Navien tankless water heater error codes and speed up your troubleshooting.

Error Code E003

What It’s Telling You

  • There is an ignition failure.

The Solution

  1. Make sure the main gas valve is completely open and there is no abnormal gas connection.

Error Code E004

What It’s Telling You

  • False flame detection.

The Solution

  1. Confirm that the main electrical cord is properly grounded.

Error Code E012

What It’s Telling You

  • There has been a flame loss.

The Solution

  1. Clean the intake filter: Remove the filter and clean it with a toothbrush under running water. Ensure the power is off before you remove the filter. Let it dry before placing it back into the unit.
  2. Check the connections: Confirm that the electrical cord is properly grounded.

Error Code E016

What It’s Telling You

  • The heat exchanger is overheating.

The Solution

  1. Restart the unit: Turn it off completely for at least 30 minutes, then restart it.
  2. Clean the inlet filter: Remove the inlet filter and clean it under running water with a toothbrush.
  3. Flush the heat exchanger: While the cold water inlet filter is out, flush the heat exchanger. Refer to your owner’s manual for specific instructions.

Error Code E030

What It’s Telling You

  • The exhaust is overheating: The unit shuts down automatically when the flue pipe exceeds a temperature of 149 degrees Fahrenheit.

The Solution

  1. Restart the unit: Turn the system off for at least 30 minutes before restarting it.
  2. Wash the inlet water filter: Remove the inlet water filter and clean it under running water with a toothbrush.
  3. Flush the heat exchanger: Consult your owner’s manual for specific instructions.

Error Code E046

What It’s Telling You

  • Unusual operation: Limit control.

The Solution

  1. Call Navien technical support at 1-800-519-8794.

Error Code E047

What It’s Telling You

  • Unusual operation: Exhaust thermostat.

The Solution

  1. Call Navien technical support at 1-800-519-8794.

Error Code E060

What It’s Telling You

  • Unusual operation: Dual venturi.

The Solution

  1. Call Navien technical support at 1-800-519-8794.

Error Code E109

What It’s Telling You

  • Unusual operation: Fan motor.

The Solution

  1. Rinse out the air intake filter: Remove the air intake filter and wash it under running water. Scrub it with a toothbrush. Let it dry and place it back into the unit.

Error Code E110

What It’s Telling You

  • Unusual air pressure.

The Solution

  1. Clear blockages: Ensure there are no obstructions in the exhaust pipe.
  2. Wash the air intake filter: Remove the air intake filter from the unit and wash it under running water. Scrub it with a toothbrush. Let it dry before placing it back.

Error Code E407

What It’s Telling You

  • An issue with the hot water outlet: This could be either an open thermistor or a short circuit.

The Solution

  1. Call Navien technical support at 1-800-519-8794.

Error Code E421

What It’s Telling You

  • A problem with the first cold water outlet: An open thermistor or a short circuit.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E432

What It’s Telling You

  • An issue with the second cold water outlet: An open thermistor or a short circuit

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E434

What It’s Telling You

  • Unusual operation: Water adjustment valve.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E438

What It’s Telling You

  • Unusual operation: Circulation pump.

The Solution

  1. External: Check that all the water return and supply lines are free and open.
  2. Internal: Check the direction of the two-way valve.

Error Code E439

What It’s Telling You

  • Unusual operation: Flow sensor.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E441

What It’s Telling You

  • An issue with the second hot water inlet: An open thermistor or a short circuit.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E445

What It’s Telling You

  • Unusual operation: Bypass mixing valve.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E515

What It’s Telling You

  • Unusual operation: Abnormal PCB behavior.

The Solution

  1. Ensure that the main electrical cord is properly grounded.

Error Code E517

What It’s Telling You

  • Unusual operation: DIP switch setting.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E593

What It’s Telling You

  • Unusual operation: Front panel key.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E615

What It’s Telling You

  • Unusual operation: Memory and input.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E736

What It’s Telling You

  • Unusual operation: Problem with internal communication.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E740

What It’s Telling You

  • Unusual operation: Outdoor temperature sensor.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E760

What It’s Telling You

  • Maintenance alarm: Flushing or service required.

The Solution

  1. Contact a local professional to perform a boiler service.

Error Code E782

What It’s Telling You

  • Unusual performance: Issue with the main panel communication.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Error Code E785

What It’s Telling You

  • Unusual performance: Issue with the flow switch/sensor.

The Solution

  1. Call Navien’s technical support at 1-800-519-8794.

Common Navien Tankless Water Heater Problems

Navien’s tankless water heaters are among the best available today, but this wasn’t always the case. Some of their pre-2011 models suffered from unfortunate issues (1). In fact, some models were even recalled (2).

Thankfully, Navien stepped up its game and issues are now far less frequent. The company was one of the first to offer tankless condensing water heaters for residential use. Problems are bound to occur when you are at the forefront of new technology, and this was the case with Navien.

If you have a pre-2011 model, here are some key issues you should look out for — or might have already experienced.

Turn The Power Off

Before doing anything else with your unit, make sure the power is off. Although it is a gas-powered boiler, it still uses electricity. To stay safe while working on your boiler, switch the breaker to the “Off” position.

1. Motherboard and Control Board Failure

A common issue involves the motherboard, control board, or sometimes both. These are the “brains” of the tankless unit, receiving and transferring information. Unfortunately, when these fail, it could mean that there’s a larger flaw with the boiler.

On Navien’s pre-2011 models, this seems to happen quite frequently. The symptoms are relatively easy to spot. Your unit will likely turn on and off repeatedly.

If it doesn’t switch on and off, check the display for error code E003 — the code for ignition failure. The simplest way to fix this is by unplugging the unit, waiting a while, and then reconnecting it.

If this doesn’t fix the issue, the control board will likely need replacing. Contact your installer for assistance.

2. Flow Sensor Corrosion

One of the most common issues with the company’s earlier models affected the flow sensors. They were made from a material that was prone to corrosion.

A flow sensor is an important part of any tankless water heater. Its main job is to detect an incoming flow of water and then activate the unit.

As Navien’s flow sensors corroded prematurely, they caused the units to shut down. A buildup of corrosion would inhibit the boiler’s operation, which could lead to other issues.

There’s one quick and easy fix to this issue but it’s only temporary. You need to turn the unit off, locate the flow sensor, gently pull it out and then blow on it. Then, place it back into the unit and turn on the power.

Navien provided a more permanent solution to this problem by improving the flow sensor material. Navien now uses stainless steel, which is resistant to rust and corrosion. If you have an older unit, you might be able to replace the part with a new one.

If this isn’t an option for you, purchase a 5-micron filter and install it by the water inlet valve.

3. Heat Exchanger Cracking

Fortunately, this problem isn’t as common as the previous two. However, it is still an issue you should be aware of.

If the heat exchanger begins to crack, it means there is a breach and harmful exhaust gasses could leak into your home. An immediate replacement is needed and there are no quick fixes to this problem. Contact Navien, as the heat exchanger should be under warranty.

How to Reset a Navien Tankless Water Heater

If there is an issue with your unit but it doesn’t display an error code, you can try resetting it. This is very easy and doesn’t require you to physically open up your heater.

Navien has made its units very user-friendly by adding a reset button on the front control panel. It is usually in the bottom corner opposite the “On/Off” button. To reset your unit, simply press the reset button and it should soon be ready to go (3).

If you have tried this and none of the listed error codes apply, contact an authorized technician.

Where is the Serial Number on a Navien Water Heater?

It is very important to know the serial number of your water heater, especially if you need to contact the manufacturer.

Finding the label with the serial number shouldn’t take long. It is usually on either the front door or the side.

Look at the side of your unit. There should be a large yellow label that contains the energy guide and any warnings. The serial number should be nearby.

Don’t worry if it isn’t on the side, as the exact location depends on the specific unit. It is often on the outside but with other units, you might need to open the unit’s door.

FAQs

Navien Tankless Water Heater Error Codes (1)

How Do You Troubleshoot a Navien Water Heater?

There shouldn’t be too much guesswork involved when troubleshooting a Navien water heater as long as the unit is still receiving electricity. The unit’s front panel should display an error code when an issue occurs which corresponds to a specific problem with your boiler. Look for the error code in our list and you should be able to determine the issue.

Navien Tankless Water Heater Error Codes (2)

Where Is the Reset Button on a Navien Tankless Water Heater?

The reset button of a Navien tankless water heater is usually located on the control panel, in the bottom corner opposite the “On/Off” switch. This means you won’t need to physically open up your heater unit, so resetting the heater should be one of your first troubleshooting tactics before you advance to more complicated methods.

Navien Tankless Water Heater Error Codes (3)

How Long Do Navien Tankless Water Heaters Last?

Tankless water heaters usually have a considerably longer lifespan than their tank counterparts. This is because tanks are subjected to more corrosion, which eventually causes holes and leaks. As tankless water heaters are in contact with water for a much shorter period, they should last 15 to 20 years and perhaps longer with proper maintenance.

Navien Tankless Water Heater Error Codes (4)

Is Navien a Good Brand of Water Heaters?

Navien is considered to be a good brand of water heaters because they offer great value for the price you pay. Navien has been in business for more than 30 years, during which time they have developed considerable competence in the field of their product category.

People with large households or who live in an area with high energy expenses will find that the tankless water heaters manufactured by Navien are an excellent investment.

In addition to this financial advantage, numerous customers have reported that their monthly costs have decreased because the heating capability of their Navien has been used for several items in their homes.

Navien Tankless Water Heater Error Codes (5)

How Long Is Navien Warranty?

Navien warranty offers a 5-year coverage for their parts and 15-year coverage for the heat-exchanger. Only Navien can authorize the replacement of the product or any of its components while the appropriate warranty period is still in effect.

If it or any of its components need to be replaced, Navien does not give permission to any other individual or business to take on any obligations or responsibilities on its behalf.

Navien Tankless Water Heater Error Codes (6)

What Maintenance Is Required for a Navien Tankless Water Heater?

To ensure a long lifespan for your Navien tankless water heater, you have to clean the inlet water screens, the air filter, and the condensate trap.

When flushing water heaters and the domestic hot water side of combi-boilers, a pump is utilized to recirculate a flush solution through the heat exchangers to complete the process.

It is important to check the quality of the water in the boiler, and heat exchangers should be cleaned as necessary.

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Navien Tankless Water Heater Error Codes (2024)

FAQs

Navien Tankless Water Heater Error Codes? ›

If the unit detects an issue, it will shut down and display an error code on the front display. To reset the water heater, press the RESET button on the front control panel. On newer units the reset button is labled as a return arrow. The unit will attempt to restart after resetting, and may resume operating.

How to clear error code on Navien tankless water heater? ›

If the unit detects an issue, it will shut down and display an error code on the front display. To reset the water heater, press the RESET button on the front control panel. On newer units the reset button is labled as a return arrow. The unit will attempt to restart after resetting, and may resume operating.

Where is the reset button on a Navien? ›

Typically, the reset button on a Navien boiler will be on its front panel, near the control display. The reset button's precise position on your boiler unit will vary based on the Navien model you own, so it's a good idea to check the instruction manual for the exact location.

How to fix E110? ›

To resolve this, bleed your radiators of air and reset the boiler. The error code should then disappear. E110, E125, and E131 error codes signify potential overheating issues in boilers. To resolve this, immediately turn off the boiler and bleed radiators to release trapped air, optimising water circulation.

What does E 001 mean on Navien tankless water heater? ›

Error code E001 on a Navien water heater typically indicates an issue with the flame detection sensor. This error can occur due to a malfunctioning sensor or improper flame detection (JustAnswer). The flame detection sensor plays a crucial role in ensuring the safe and efficient operation of the water heater.

What is error code 111 on tankless? ›

If you run into error code 111, it means your Takagi tankless water heater is experiencing ignition failure. This basically means that the burner cannot light, which could be linked to a couple of different issues. Error code 111 can be triggered by not providing the gas supply or gas valve an adequate amount of gas.

What is the code E0 on a tankless water heater? ›

The E0 error code can be the result of a power surge or power outage or interruption. This code can frequently be resolved by turning off the unit and unplugging it from the wall for 30 seconds. This needs to be done with the faucets turned off and no water flowing through the unit.

How do you clear Navien error codes on a water heater? ›

Common Navien Tankless Water Heater Error Codes:

The reset button is typically located on the control panel of the unit. Pressing and holding the reset button for several seconds should reset the unit and clear any persistent issues.

How long do Navien tankless water heaters last? ›

Like all water heating products, tankless water heaters require some maintenance to ensure proper operation, peak efficiency, and product longevity. Navien tankless water heaters can last more than 20 years with proper maintenance.

How do you troubleshoot a Navien tankless water heater? ›

Is Your Navien Tankless Water Heater Reporting Errors?
  1. Check if the manual gas valve is open.
  2. Check the main gas supply.
  3. For your safety and the health of your equipment, Call or Contact Hot Water Now! ...
  4. Verify that gas pressure is within operating range.
  5. Check Dual Venturi for proper operation.
  6. Check DIP Switch settings.

Why is my Navien water heater blinking red but no error code? ›

The flashing red light indicates the unit has powered down to prevent damage. Navien heaters have a high limit switch that will shut off the burner if the internal temperature exceeds 190°F. This safety mechanism prevents dangerous overheating.

What is the error code for Navien PCB? ›

515-09 is a “diagnostic code” that indicates issues with the Navien tankless water heater or combi boiler's PCB unit. It requires immediate attention to ensure the appliance operates efficiently and safely.

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