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Fixing Navien Error Code 515-09 Abnormal PCB- A Complete Guide

Navien Error Code 515-09 Abnormal PCB

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Since you are here, we take it as a sign that your Navien tankless water heater or boiler is displaying 515-09 error code. Indeed, understanding the Navien 515-09 error code is crucial for homeowners and service technicians, as it makes troubleshooting easier. This error code signifies malfunctioning, which in turn, leads to poor performance. Read this article to find out everything about Navien error code 515-09 abnormal PCB, including why it occurs and how to fix it.

Let’s get started!

What is Navien Error Code 515-09?

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.

When Navien error code 515-09 abnormal PCB occurs, the unit’s primary response is to shut down to avoid any potential safety hazards or further damage. Here’s exactly what might happen as a result:

Cold Water – The most noticeable effect of this Navien error is that your water heater or combi-boiler will not produce hot water. This can be inconvenient, primarily if you rely on hot water for daily activities, such as showers, dishwashing, and laundry.

Shutdown – The Navien unit typically shuts down as a safety precaution when a 515-09 error is displayed. This shutdown is intended to prevent further issues or damage if the unit continues to operate with the identified problem.

Error Code Display – The unit’s control panel or display will show the specific error code “515-09.” This code is a diagnostic tool to help homeowners and service technicians identify the underlying issue.

Lockout – In some cases, the unit may go into a lockout mode, where it remains inoperable until the issue is resolved and the unit is manually reset. This is another safety measure to prevent unsafe operations.

Possible Gas Odor – You may detect a faint gas odor around the appliance when a Navien pcb error occurs. This is an additional safety feature designed to alert you to the presence of a gas-related problem.

How to Fix Navien Error Code 515-09 Abnormal PCB?

Navien error codes are designed to pinpoint specific problems—making it easier to identify and address issues with your water heater or combi-boiler. Thus, when it specifically shows the Navien error code 515-09 abnormal PCB, you can do the following to fix it:

Step 1 – Check the gas supply to the Navien unit is open and sufficient. If the gas valve is closed, open it and verify that the gas pressure is within the recommended range.

Step 2 – Examine the flame rod for any dirt or corrosion. Clean it gently if necessary. You need to verify that the flame rod is positioned correctly and making good electrical contact.

Step 3 – Inspect the venting system for any obstructions, such as debris or animal nests. Just ensure that the venting is clear and functioning correctly.

Step 4 – Check ignition components, such as igniter and gas valve for any issues or damages. It is better to replace any faulty components as needed.

Step 5 – Carefully inspect the wiring and connections within the unit. Try looking for loose or damaged wires and repair or replace them as required.

Step 6 – Reset the unit after addressing any potential issues. This can sometimes clear the error code if the problem has been resolved.

Navien Error Code 515-09 Abnormal PCB

What Else to Do?

Here are some additional tips that you may follow to make Navien error code 515-09 abnormal PCB troubleshooting hassle-free, safe, and quick:

Safety First – Always prioritize safety while troubleshooting anything. So, if you’re uncertain about handling gas-related components or electrical connections, it’s best to contact a certified Navien service technician for assistance.

Ensure Regular Maintenance – If you want to prevent error codes like 515-09 and ensure your Navien unit’s long-term performance, schedule regular maintenance. This includes cleaning filters, inspecting for debris, and addressing any potential issues promptly.

Consult the Manual – Refer to your Navien user manual for specific troubleshooting steps and guidelines provided by the manufacturer. Do not follow any random advice or recommendations.

Selecting higher quality PCBs: Choose high-quality PCBs from trusted producers such as MKTPCB to ensure the best performance and durability for your water heater system.

Get Professional Help – If you have attempted troubleshooting and the error code persists, or if you’re uncomfortable performing specific tasks, don’t hesitate to reach out to a qualified Navien service technician. They have the expertise and tools to diagnose and resolve complex issues.

Other Navien Error Codes You May Encounter

Navien provides a comprehensive set of error codes to help you diagnose and address these problems. In addition to Navien error code 515-09 abnormal PCB, there are several other Navien error codes that you should be aware of:


This error indicates a problem with the ignition process in the Navien water heater. Its common causes include ignition electrode issues, dirty or faulty flame rod, insufficient air supply, etc. Here’s what you can do to fix the Navien E001 error:

  • Check gas supply and pressure.
  • Clean or replace the ignition electrode.
  • Inspect and clean flame rod.
  • Ensure proper ventilation and air supply.
  • Examine and repair/replace gas valve if needed.
  • Inspect wiring connections.


This error signifies a failure in maintaining the flame within the heater, leading to heating issues. Its common causes include a lack of gas supply, dirty or faulty flame rod, blocked exhaust vent, and wiring problems. Follow these quick tips to fix Navien E003 error:

  • Check the gas supply and valve.
  • Clean igniter and flame rod.
  • Inspect the exhaust vent for obstructions.
  • Reset the unit.
  • Review error codes in the manual.
  • Contact a professional if the issue persists.


This error code indicates a flow sensor issue. It may be triggered by a defective flow sensor, blocked water flow, or a damaged wiring connection. Fix it by following these:

  • Check for a defective flow sensor.
  • Inspect for blocked water flow.
  • Examine wiring connections for damage.


If you see this code, it signifies an overheating issue. It’s essential to check if the unit’s vents are obstructed and that there’s proper ventilation. Here’s how you can attempt to fix this error:

  • Remove any obstructions from the vents.
  • Ensure there’s ample space around the unit for better air circulation.
  • Lower the room temperature to alleviate overheating.


This code relates to the air pressure sensor. It can be caused by issues with the sensor itself or improper venting. You can fix E030 error in the following ways:

  • Check the air pressure sensor for issues.
  • Ensure proper ventilation for the unit.


The E032 code points to a dual or cascade system communication problem. If you have multiple Navien units connected together, this error suggests that they are not communicating properly. Here are some quick ways to fix this Navien error:

  • Examine the wiring and connections between the Navien units.
  • Try resetting the communication settings between the units.
  • Ensure that the units are configured correctly for dual/cascade operation.


When the E038 error code appears, it means there’s an issue with the circulation pump. Try doing these while troubleshooting this error:

  • Check circulation pump operation.
  • Inspect pump wiring and connections.
  • Verify pump settings and configurations.

There are many more error codes, such as the E039 error, which indicates a circulation pump motor problem. Moreover, there can be an E060 error code related to issues with Abnormal PCB Navien. Professional assistance may be required to diagnose and resolve issues with the electronic components.


Navien Error Code 515-09, indicating an abnormal PCB issue in your Navien water heater or combi boiler, can disrupt your hot water supply and pose safety concerns. However, with the right troubleshooting steps, like checking the gas supply, cleaning components, and ensuring proper ventilation, you can fix the Navien error code 515-09 abnormal pcb. While you diagnose Navien abnormal pcb connection, make sure to prioritize safety, consider regular maintenance, and consult your user manual for guidance. In complex cases, it is better to seek professional assistance to ensure the optimal performance of your appliance.

Frequently Asked Questions


How to check Navien error codes?

Checking Navien error codes is easier and simpler than you think. Here’s what you can do to check Navien error codes:

  • Find the control panel on your Navien water heater. This is usually located on the front of the unit.
  • The next step would be to access the Diagnostic Menu. If you cannot find it, consult your user manual for the exact procedure, as it can vary between models.
  • Once you have accessed the diagnostic menu, you will be able to view error codes on the display screen. The error code will typically be displayed as a combination of numbers and letters.
  • Take note of the code that is displayed and then refer to your Navien user manual or the manufacturer’s documentation to interpret the error code. The manual should provide information on what each code signifies and its possible causes.

How do you clear Navien error codes?

Once you have identified the Navien error code, you can quickly resolve the underlying issue that triggered it. However, it is not recommended to attempt clearing it without technical knowledge. But if you have basic know-how, follow these steps to clear Navien error codes in real-time:

  • First of all, address the root cause of the error code. For example, if you have error code 515-09 due to a flow sensor issue, ensure that the water flow is restored and any obstructions are removed.
  • After this, turn off the power to your Navien water heater. Simply press the button or switch on the control panel to do it.
  • Keep it turned off for a few minutes, giving the system time to reset.
  • Turn the unit back on by pressing the power button or flipping the power switch.
  • Lastly, monitor the control panel to see if the error code has cleared. The error code should no longer be displayed if the issue has been successfully resolved. If the error code persists, the problem still exists and requires further attention.
  • Call a technician to seek professional help. Do not get involved further if you are not sure what to do and how.

Is error code 515-09 a common problem with Navien water heaters?

Error code 515-09 is not very common, but it can occur due to various factors—such as water flow issues or sensor problems. If you’d like to prevent it from occurring, then regular maintenance and proper installation can help. Just keep a check!

Can I continue using water heater with Navien error code 515-09 abnormal PCB issue?

Using your Navien water heater when error code 515-09 is displayed is not recommended, as it may indicate a problem with the PCB unit’s performance. This can lead to further damage and higher repair costs. Have it fixed first.

Is error code 515-09 covered under Navien’s warranty?

It depends on the specific terms and conditions of your Navien warranty. Generally, if the issue is due to a manufacturing defect or a covered component, it may be eligible for warranty repair or replacement. Check your warranty documentation to confirm whether Navien error code 515-09 abnormal PCB is covered or not.


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