Navien Error Codes

Navien Error Codes: A Guide to Help You Easy Fixing

  • Understanding the Navien error codes is crucial for maintaining their optimal performance.
  • Error codes in tankless water heaters enhance the user experience and prolong the appliance’s lifespan.
  • Understanding Navien error codes is vital for efficient troubleshooting and maintaining the optimal performance of your tankless water heater. 
  • Regular preventive maintenance is critical to ensuring the smooth operation and longevity of your Navien tankless water heater

Tankless water heaters, also known as on-demand water heaters, have revolutionized how we experience hot water in our homes. 

Table of Contents

I. Introduction

Understanding the Navien error codes is crucial for maintaining their optimal performance. These error codes serve as the unit’s communication method, alerting users to potential issues or malfunctions. By decoding these error codes, homeowners can troubleshoot problems effectively and take timely action to prevent further complications.

Tankless water heaters, also known as on-demand water heaters, have revolutionized how we experience hot water in our homes. Traditional water heaters store and heat a fixed amount of water. On the other hand, tankless water heaters heat water directly as it flows through the unit. This means you can have a continuous hot water supply whenever needed.

Navien: The brand you trust

One prominent player in the realm of tankless water heaters is Navien. With a reputation for innovation and quality, Navien has established itself as a famous brand in the industry. Their tankless water heaters are known for their energy efficiency, space-saving design, and advanced features.

We’ll explore the error codes Navien tankless water heaters can display and their possible causes and solutions. We will provide insights into common error codes that users might encounter. We unravel the mysteries behind each code and equip you with the knowledge needed to address these issues. By grasping the significance of error codes, you’ll ensure the longevity of your Navien water heater.

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The chart above shows the most popular water heaters used by construction firms in the U.S., according to Statista.

II. Understanding Navien Error Codes

Error codes in tankless water heaters enhance user experience and prolong the appliance’s lifespan. These codes communicate between the water heater and the homeowner, providing valuable insights into the unit’s health and functionality.

The primary purpose of error codes is to alert users when the water heater encounters a problem or anomaly. This real-time feedback mechanism empowers homeowners to take swift action in the face of potential issues. In the process, minor glitches are prevented from escalating into significant malfunctions. By deciphering these error codes, users can promptly diagnose the source of the problem. This gives them the leeway to decide whether it’s something they can address on their own. Or if professional assistance is required.

Error codes also act as a preventive measure, helping mitigate further water heater damage. Early detection of a problem can prevent the unit from running under compromised conditions, ultimately safeguarding its performance and efficiency. For instance, a code indicating inadequate water flow might lead the user to check for clogged filters.

By understanding Navien error codes, homeowners can take proactive steps to maintain their tankless water heaters at their best. This knowledge empowers them to make informed decisions about troubleshooting and repair. 

III. Common Navien Error Codes and Their Meanings

Understanding Navien error codes is vital for efficient troubleshooting and maintaining the optimal performance of your tankless water heater. This comprehensive list of error codes, meanings, and solutions is a valuable resource for promptly and effectively addressing issues. Here is a list of Navien water heater Error codes and their meaning.

Let’s explore these error codes and how to tackle them:

1. Navien Error Code 003: Flow Sensor Issue

Potential Reasons:

Insufficient water flow, damaged flow sensor.


Limited hot water, fluctuating water temperature.


Check for water supply and pressure issues, and clean the inlet water filter.


If the Navien 003 error code persists, contact a professional technician for flow sensor replacement.

2. Navien Error Code E110: Exhaust Blockage

Potential Reasons:

Blocked venting system and exhaust pipe obstruction.


Heater shutdown, error code display.


Inspect the venting system for blockages or restrictions.


To resolve the Navien e110 error code, clear any obstructions, ensure proper venting installation and check for exhaust leaks.

3. Navien Error Code 302: Ignition Failure

Potential Reasons: 

Gas supply issues, electrode problems, ignition failure.


The heater is not producing hot water, despite repeated ignition attempts.


Check the gas supply, inspect ignition components, and clean electrodes.


Address gas supply problems and clean or replace faulty ignition components as needed.

4. Navien Error Code 598: Flame Rod Issue

Potential Reasons: 

Dirty flame rod, and flame detection problems.


Heater shutdown, repeated ignition attempts.


Clean the flame rod and ensure proper positioning.


If cleaning doesn’t resolve the Navien tankless error code 598, consider replacing the flame rod.

5. Navien Error Code 515-09: Water Flow Sensor

Potential Reasons:

Water flow sensor malfunctions and sensor wiring issues.


Inconsistent water temperature, limited hot water.


Inspect the water flow sensor and its wiring.


To clear the Navien 515 error code, repair or replace the water flow sensor as necessary.

6. Navien Error Code 762: PCB Issues

Potential Reasons: 

Printed circuit board (PCB) malfunction.


Erratic behavior, heater not responding.


Check connections and wiring on the PCB.


If Navien 762 error code PCB issues persist, consult a professional for repair or replacement.

7. Navien Error Code 351: Air Pressure Sensor

Potential Reasons: 

Air pressure sensor malfunctions and venting problems.


Heater shutdown, error code display.


Inspect the air pressure sensor and venting system.


To resolve the Navien 351 error code, address venting issues, and replace the air pressure sensor if needed.

8. Navien Error Code 773: Hot Water Outlet Temperature

Potential Reasons: 

High outlet temperature, sensor malfunction.


The heater shut down due to overheating.


Check for water temperature settings and inspect sensor connections.


Adjust temperature settings and replace the sensor if necessary.

9. Navien Error Code 351 (Again): Air Pressure Sensor (Different Variation)

Potential Reasons:

Air pressure sensor issues and combustion-related problems.


Heater shutdown, error code display.


Inspect the air pressure sensor and check for proper combustion.


Address combustion issues and replace the air pressure sensor if required.

10. Navien Error Code 736: Combustion Fan

Potential Reasons: 

Combustion fan malfunction, wiring issues.


The heater is not functioning, and an error code is displayed.


Check the combustion fan and its wiring.


Repair or replace the combustion fan as needed.

Please note that while these troubleshooting steps can assist in resolving minor issues, some problems may require professional attention. 

IV. Preventive Maintenance to Avoid Error Codes

Regular preventive maintenance is critical to ensuring the smooth operation and longevity of your Navien tankless water heater. Simple routine practices can significantly reduce the likelihood of encountering error codes and other issues. Here’s why proactive maintenance matters and how to keep your water heater in top shape:

1. Regular Inspections:

Schedule periodic inspections to ensure all components, such as sensors, valves, and venting systems, function correctly. Look for signs of wear, corrosion, or damage.

2. Optimal Performance:

Proper maintenance ensures your water heater operates at its peak efficiency. This translates to energy savings and a consistent hot water supply.

3. Ventilation:

Adequate ventilation is essential for safe and efficient operation. Ensure that the venting system is clear of obstructions, debris, or any potential sources of blockage.

4. Descaling:

Over time, mineral deposits can build up in the heat exchanger, affecting performance and potentially triggering error codes. Regular descaling helps maintain optimal heat transfer efficiency.

5. Water Quality:

Poor water quality can lead to sediment accumulation, which may clog the system and cause errors. Consider installing a water softener or filtration system to improve water quality.

6. Filter Cleaning:

Clean or replace filters regularly to prevent debris from clogging the water inlet, which can impact water flow and trigger error codes.

7. Professional Maintenance:

While homeowners can do many maintenance tasks, consider scheduling professional maintenance annually. Certified technicians can perform thorough checks and tune-ups and address potential issues.

V. Tips for Troubleshooting Beyond Error Codes

Error codes provide valuable insights into the functioning of your Navien tankless water heater. However, there might be instances where issues persist despite following the provided troubleshooting steps. In such cases, exploring other factors that could contribute to heater problems is essential:

1. External Factors:

Consider factors outside the water heater that could impact its performance. For instance, fluctuating water pressure, inconsistent gas supply, or electrical disruptions. Addressing these external factors can often resolve issues.

2. Ventilation Issues:

Poor ventilation can lead to improper combustion and trigger error codes. Ensure the venting system is correctly installed, free from blockages, and compliant with safety regulations.

3. Water Quality:

If you’ve experienced persistent issues, water quality might be a contributing factor. Hard water with high mineral content can lead to scale buildup, affecting the water heater’s efficiency and lifespan.

4. Overloaded System:

If your household’s hot water demands have increased significantly, your current water heater might need help to keep up. Consider upgrading to a more powerful unit if needed.

5. Aging Components:

Some issues may stem from the wear and tear of older components. If your water heater is relatively old, certain parts need replacement to restore optimal functionality.

6. Navien Customer Support:

If you’ve exhausted troubleshooting options and are still facing challenges, contact Navien’s customer support. They have a team of experts who can provide guidance and insights into complex issues.

7. Professional Inspection:

If the problem persists despite your best efforts, it’s wise to consult a professional technician. Certified Navien technicians have the expertise to diagnose and resolve intricate problems effectively.

Remember that while troubleshooting is valuable, safety should always be a priority. If you’re dealing with gas or electrical components, exercise caution and seek professional help if you’re uncomfortable with the tasks.

VII. Resources and References

For further assistance and in-depth information about Navien tankless water heaters and error codes, consider exploring the following resources:

1. Navien Official Website: The official Navien website is a reliable source of product information, user manuals, and technical support. You can find detailed guides, FAQs, and contact information for customer support.

2. Navien User Manuals: Navien provides user manuals for their products, offering step-by-step instructions for installation, operation, and maintenance. These manuals are on their website or included with your water heater’s packaging.

3. Online Forums and Communities: Online platforms like HVAC forums, Reddit, and home improvement communities often host discussions about tankless water heaters. You can learn from others’ experiences, ask questions, and seek advice on troubleshooting.

4. Professional HVAC Technicians: You may encounter complex issues or need professional maintenance. In this case, certified HVAC technicians with expertise in Navien products can provide specialized assistance and insight.

5. Local Distributors and Dealers: Local authorized Navien distributors and dealers may offer guidance, support, and services related to installation, maintenance, and repairs.

6. YouTube Tutorials: Video tutorials on platforms like YouTube can visually guide you through specific troubleshooting steps. They also include maintenance tasks related to Navien tankless water heaters.

Remember that accurate and up-to-date information is crucial, so always refer to official sources and trusted experts. Utilizing these resources can help you navigate any challenges you might face with your Navien tankless water heater and ensure its smooth operation for years.


1. What does DHW Wait mean on Navien?

“DHW Wait” on a Navien water heater refers to when the unit delays the delivery of Domestic Hot Water (DHW). This delay is intentional and is usually associated with certain operational aspects of the water heater.

2. How to reset a Navien tankless water heater?

Resetting a Navien tankless water heater can vary slightly depending on the specific model and the reason for the reset. Here’s a general procedure that you can follow to reset a Navien tankless water heater:

  • 1. Power Off the Unit:
  • 2. Wait for a Few Minutes:
  • 3. Power On the Unit:
  • 4. Monitor the Display:
  • 5. Check for Normal Operation:

3. Why does my Navien water heater keep shutting off?

A Navien water heater may shut off for various reasons, which can help you troubleshoot the issue. Here are some common factors that can cause a Navien water heater to shut off:

  • 1. Ignition Failure
  • 2. Flame Detection Problems
  • 3. Overheating
  • 4. Air Intake/Exhaust Issues
  • 5. Gas Supply Problems
  • 6. Electrical Problems
  • 7. Water Flow Issues
  • 8. Error Codes
  • 9. Component Wear

4. What is the error code for Navien flame loss?

The error code associated with a flame loss or failure to ignite on Navien tankless water heaters can vary depending on the specific model and series. However, a standard error code that indicates flame loss on Navien units is usually “E003.”

5. What is the air code for Navien?

The “air code” you are referring to might be related to the air intake/exhaust systems of a Navien tankless water heater. In many cases, a Navien water heater may display an error code related to ventilation or air supply issues. These codes can indicate combustion, air flow, or exhaust problems.

VI. The Crux of the Discussion:

In this comprehensive guide, we’ve explored the world of Navien tankless water heater error codes. We delved into their meanings, troubleshooting methods, and preventive measures. Let’s recap the key takeaways from this article:

Understanding Navien error codes is vital for maintaining the optimal performance of your tankless water heater. These codes serve as a communication bridge, alerting you to potential issues and enabling timely intervention.

We’ve covered a range of standard error codes, such as 003, E110, 302, 598, 515-09, 762, 351, 773, and 736, offering insights into their causes, symptoms, troubleshooting steps, and solutions. By following our guidance, you can address these issues effectively and prevent unnecessary disruptions in your hot water supply.

Preventive maintenance emerged as a critical aspect of ensuring error-free operation. By conducting routine inspections, maintaining proper ventilation, descaling, and upholding water quality, you can prevent problems before they arise.

However, we also acknowledged that some issues may require professional intervention. External factors, ventilation problems, and water quality can all contribute to complications beyond error codes. In such cases, reaching out to Navien customer support or certified technicians is prudent.

Final Verdict:

In conclusion, understanding Navien error codes empowers you to take control of your tankless water heater’s performance. By proactively troubleshooting, maintaining your system, and seeking assistance when necessary, you can enjoy a consistent hot water supply and extend your appliance’s lifespan.

We encourage you to bookmark this article as a valuable reference for future troubleshooting needs. With this resource at your fingertips, you’ll be well-equipped to address any challenges and continue enjoying the benefits of your Navien tankless water heater to the fullest.

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