Navien Error Code 515-09 Abnormal PCB - Complete Fix Guide

If your Navien tankless water heater or boiler is showing the error code 515-09, it’s important to understand what it means and how to address it. The Navien Error Code 515-09 indicates an “Abnormal PCB,” meaning there is a malfunction with the Printed Circuit Board (PCB) of your unit. This error can affect the performance of your system, causing issues like a lack of hot water and even a system shutdown. Understanding the causes of this error and how to fix it will help you restore your Navien water heater or combi boiler to optimal functioning.

What Is Navien Error Code 515-09?

Navien Error Code 515-09 Abnormal PCB is a diagnostic code that points to a problem with the PCB (Printed Circuit Board) in your Navien tankless water heater or combi boiler. The PCB is the main control unit that manages various functions of your appliance. When this error code appears, it signals a malfunction, which could lead to serious issues with your unit's performance, if not addressed promptly. This issue can lead to the system shutting down, potentially affecting the water heater's ability to heat water, thus disrupting daily tasks such as showers, laundry, or dishwashing.

What Happens When Navien Error Code 515-09 Occurs?

When the Navien Error Code 515-09 is detected, the system typically shuts down as a safety precaution. This is done to prevent further damage or safety risks from occurring. Here are the main consequences you may face when the error appears:

1. No Hot Water: One of the most noticeable effects of the 515-09 error is that your Navien unit will stop producing hot water. This can be inconvenient for basic tasks such as showering, washing dishes, or doing laundry.

2. System Shutdown: The Navien unit will automatically shut down upon detecting this error. The shutdown prevents the system from running in a malfunctioning state, which could lead to greater damage.

3. Display of Error Code: The control panel of your Navien appliance will display the 515-09 error code. This acts as a diagnostic tool for both homeowners and service technicians to identify the issue.

4. Lockout Mode: Some units may enter lockout mode, which means the system will not operate again until the error is fixed and the unit is manually reset.

5. Potential Gas Odor: In rare cases, you might notice a faint gas odor around your unit due to the malfunction. This is a safety feature to alert you to potential gas-related issues, which may arise from the malfunctioning PCB.

How to Fix Navien Error Code 515-09 Abnormal PCB

The 515-09 error points to a problem with the PCB in your Navien unit. Fortunately, with some troubleshooting steps, you can often resolve the issue yourself. Follow these steps to help fix the problem:

Step 1 – Check the Gas Supply

Ensure that the gas supply to the Navien unit is open and working correctly. If the gas valve is closed, open it and confirm that the gas pressure is within the recommended range. A proper gas flow is crucial for your unit to function correctly.

Step 2 – Inspect the Flame Rod

The flame rod may be dirty or corroded, which can affect its ability to detect the flame during ignition. Clean it carefully, and ensure it is positioned correctly and making good electrical contact. A faulty flame rod can prevent your unit from igniting, leading to an error code.

Step 3 – Examine the Venting System

Inspect the venting system for any blockages. Blockages such as debris or even animal nests can obstruct the airflow and prevent the system from functioning properly. Clear any obstructions to ensure proper ventilation, which is essential for safe operation.

Step 4 – Check Ignition Components

Inspect the igniter and gas valve for any signs of damage or malfunction. If you notice any problems, replace the damaged parts to prevent further issues and restore the system to working order.

Step 5 – Inspect Wiring and Connections

Check the wiring and connections inside the unit. Loose or damaged wires can prevent the unit from working correctly, so be sure to repair or replace any problematic wiring.

Step 6 – Reset the Unit

After addressing any potential issues, try resetting the unit. Often, simply resetting the system can clear the error code if the problem has been resolved.

By following these steps, you can often fix the 515-09 error and get your Navien water heater or combi boiler running again.

Additional Tips for Troubleshooting Navien Error Code 515-09

Here are some additional tips to help troubleshoot the Navien 515-09 error code:

• Prioritize Safety: Always be cautious when troubleshooting any appliance. If you are unsure about handling gas or electrical components, it's best to contact a certified Navien technician. They can handle the job safely and effectively.

• Schedule Regular Maintenance: To prevent issues like the 515-09 error and ensure your Navien unit operates efficiently, schedule regular maintenance. This includes cleaning filters and inspecting for debris. Regular maintenance can help extend the lifespan of your system and reduce the likelihood of future errors.

• Consult the User Manual: Your Navien user manual contains valuable troubleshooting tips and guidelines specific to your model. It’s important to follow the manufacturer’s instructions to resolve error codes accurately.

• Get Professional Assistance: If you’re unable to resolve the issue on your own or if the error code persists, don’t hesitate to call a professional. A qualified Navien technician can diagnose and fix more complex problems, ensuring that your unit is repaired safely.

Other Navien Error Codes You May Encounter

In addition to the 515-09 error, there are several other error codes you might come across in a Navien unit. Here’s a breakdown of some common ones and how to address them:

• E001 – Ignition Failure: This error occurs when the ignition process fails. Check the gas supply, clean the flame rod, and inspect the igniter and gas valve.

• E003 – Flame Failure: This happens when the unit fails to maintain a stable flame. Check for a gas supply issue, clean the igniter, and inspect the exhaust vent for blockages.

• E010 – Flow Sensor Issue: The flow sensor could be defective or obstructed. Check the sensor, look for blockages in the water flow, and inspect wiring connections.

• E016 – Overheating: This error indicates an overheating issue. Check for blocked vents, clear any obstructions, and ensure proper ventilation.

• E030 – Air Pressure Sensor Error: This error occurs due to an issue with the air pressure sensor or improper venting. Check the sensor and ensure adequate ventilation.

• E038 – Circulation Pump Error: This error points to a malfunctioning circulation pump. Inspect the pump and its wiring connections.

For other errors like E039, E060, or E032, professional assistance may be necessary to diagnose and resolve the issue accurately.

Conclusion: Fixing Navien Error Code 515-09

Navien Error Code 515-09 signals a problem with the PCB in your Navien water heater or combi boiler. If not addressed promptly, it can lead to a loss of hot water and potential safety risks. By following the troubleshooting steps outlined above—checking the gas supply, cleaning components, inspecting wiring, and resetting the system—you can often resolve the error and restore your system’s functionality.