How To Fix Navien Tankless Water Heater Code E003?

Navien tankless water heaters are known for their energy efficiency, space saving, and endless hot water supply. However, like any other appliance, they may encounter some problems from time to time. One of the common issues that many Navien users face is the code E003, which indicates an ignition failure.

If your Navien tankless water heater displays the code E003, it means that the unit is not able to ignite and heat the water. This can result in no hot water, cold water, or unit shutdown. This can be very frustrating and inconvenient, especially when you need hot water for your daily activities.

Fortunately, there are some simple steps that you can follow to troubleshoot and fix this error code. In this blog post, I will show you how to fix Navien tankless water heater code E003 and what causes it. I will also give you some tips on how to prevent this error code from happening again.

By following this guide, you can restore your hot water supply and enjoy your Navien tankless water heater without any hassle.

What Causes Navien Tankless Water Heater Code E003?

The code E003 on Navien tankless water heater means ignition failure. This means that the unit is not able to ignite the gas in the burner chamber and heat the water. There are several possible causes for this error code, such as:

• No gas or insufficient gas supply
• Bad flame rod wiring or the flame rod itself is bad
• Bad PC or motherboard

Let’s take a closer look at each of these causes and how to fix them.

No Gas or Insufficient Gas Supply

One of the most obvious reasons for the code E003 is that there is no gas or insufficient gas supply to the unit. Without gas, the unit cannot ignite and heat the water.

This can happen if the gas valve is closed, partially open, or faulty. It can also happen if the gas tank is empty or low on gas.

How To Fix:

To fix this issue, you need to check the gas supply and the gas valve on your Navien tankless water heater. Here are the steps to do so:

• Locate the gas valve on your unit. Depending on your model, it may be on the front panel or inside the unit. You may need to remove a cover or a panel to access it.
• Make sure the gas valve is fully open and not closed or partially open. If it is closed or partially open, turn it counterclockwise to open it fully and allow the gas to flow to the unit.
• Check the gas tank or source and make sure there is enough gas for your unit. If the gas tank is empty or low on gas, refill it with gas or replace it with a full one.
• Connect a manometer to the pressure port on your unit and check the inlet gas pressure. The inlet gas pressure should be within the range specified by your unit’s manual. If it is too low or too high, adjust it accordingly or contact a professional for assistance.

Bad Flame Rod Wiring Or The Flame Rod Itself Is Bad

Another possible cause for the code E003 is that the flame rod wiring or the flame rod itself is bad. The flame rod is a device that senses the presence of a flame in the burner chamber and sends a signal to the control board to keep the gas valve open. The flame rod wiring is a thin black wire that connects the flame rod to the control board.

If either of these devices is damaged, dirty, or defective, they may not be able to detect or communicate the flame status and cause the unit to display the code E003.

How To Fix:

To fix this issue, you need to inspect, clean, test, and replace (if needed) the flame rod wiring and the flame rod on your Navien tankless water heater. Here are the steps to do so:

• Turn off your unit and disconnect it from power.
• Remove the front panel and unscrew the blower assembly of your unit. You may need a screwdriver or a wrench for this step.
• Locate the flame rod assembly on your unit. It consists of a thin black wire (flame rod wiring) and a metal rod (flame rod) that protrudes into the burner chamber.
• Visually inspect the flame rod wiring and look for any signs of Sure, I can continue writing the blog post. Here is the continuation of the blog post:
• damage, dirt, or corrosion. If the wiring is damaged or pinched, it may not be able to send the signal to the control board. If the wiring is dirty or corroded, it may interfere with the signal transmission.
• Use a soft brush or a cloth to gently clean the flame rod wiring and remove any dirt or corrosion. Do not use any abrasive or corrosive materials that may damage the wiring.
• Use a multimeter to test the resistance and voltage output of the flame rod wiring. The resistance should be within the range specified by your unit’s manual. The voltage output should be around 1.5 V when exposed to a flame. If the resistance or voltage is too low or too high, the wiring may be defective and need to be replaced.
• Visually inspect the flame rod and look for any signs of damage, dirt, or corrosion. If the flame rod is damaged or bent, it may not be able to sense the flame properly. If the flame rod is dirty or corroded, it may affect its sensitivity and performance.
• Use a soft brush or a cloth to gently clean the flame rod and remove any dirt or corrosion. Do not use any abrasive or corrosive materials that may damage the flame rod.
• Use a multimeter to test the resistance and voltage output of the flame rod. The resistance should be within the range specified by your unit’s manual. The voltage output should be around 1.5 V when exposed to a flame. If the resistance or voltage is too low or too high, the flame rod may be defective and need to be replaced.
• If you need to replace the flame rod wiring or the flame rod, make sure you use compatible parts from Navien or an authorized dealer. Follow the instructions in your unit’s manual or contact a professional for assistance.
• Reassemble your unit and turn it on. Check if the code E003 is cleared and if your unit is working properly.

Bad PC Or Motherboard

The third possible cause for the code E003 is that the PC or motherboard of your Navien tankless water heater is bad. The PC or motherboard is the main control board that regulates all the functions and operations of your unit. It also displays and stores any error codes that may occur.

If the PC or motherboard is faulty or damaged, it may not be able to control or communicate with other components of your unit, such as the gas valve, the igniter, and the flame rod. This may result in ignition failure and code E003.

How To Fix:

To fix this issue, you need to inspect, test, and replace (if needed) the PC or motherboard on your Navien tankless water heater. Here are the steps to do so:

• Turn off your unit and disconnect it from power.
• Remove the front panel and locate the PC or motherboard on your unit. Depending on your model, it may be on a metal plate behind a plastic cover or on a metal box near the bottom of your unit.
• Visually inspect the PC or motherboard and look for any signs of damage, burn marks, loose wires, or corrosion. If you see any of these signs, it may indicate that the PC or motherboard is bad and need to be replaced.
• Use a multimeter to test the voltage output of the PC or motherboard. The voltage output should be within the range specified by your unit’s manual. If the voltage is too low or too high, the PC or motherboard may be defective and need to be replaced.
• If you need to replace the PC or motherboard, make sure you use compatible parts from Navien or an authorized dealer. Follow the instructions in your unit’s manual or contact a professional for assistance.
• Reassemble your unit and turn it on. Check if the code E003 is cleared and if your unit is working properly.

How To Prevent Navien Tankless Water Heater Code E003?

Now that you know how to fix Navien tankless water heater code E003, you may wonder how to prevent it from happening again. Here are some tips that can help you avoid this error code and keep your unit in good condition:

• Perform regular maintenance on your unit according to your unit’s manual or manufacturer’s recommendations. This includes cleaning the air filter, the flame rod, and the heat exchanger, checking the gas pressure and the water flow, and replacing any worn or damaged parts.
• Use only high-quality gas and water for your unit. Avoid using gas or water that contains impurities, contaminants, or additives that may affect the performance or lifespan of your unit.
• Install a surge protector on your unit to protect it from power surges or fluctuations that may damage the PC or motherboard.
• Install a water softener on your unit to prevent hard water buildup that may clog the pipes, valves, or filters of your unit.
• Install a gas regulator on your unit to prevent gas pressure spikes that may damage the gas valve or other components of your unit.

Conclusion

I hope this blog post has helped you understand how to fix Navien tankless water heater code E003 and what causes it. By following these simple steps, you can troubleshoot and fix this error code and enjoy your hot water without any hassle.

If you have any questions or feedback about this blog post, please feel free to leave a comment below. I would love to hear from you.