Top 5 Navien Tankless Water Heater Problems [Fixed]

In this article, we’re giving you a troubleshooting guide for one of the most popular tankless water heater brands – Navien. The Navien tankless water heater is renowned for its simplicity and quality. But, typical to any household appliance, it isn’t without its faults. We’ll give you a guide to understanding and fixing common problems, such as a water flow issue or any other tankless water heater problem, and the resources for fixing unknown issues.

Troubleshooting Your Navien Tankless Water Heater

Navien Tankless Water Heater Problems

Flow Sensor Is Bad 

The flow sensor is what monitors your device’s water flow, ensuring the tankless heater is heating the water to the proper temperature. The flow sensor is made up of a couple of wires, a probe and some connectors.

I have found flow sensors rarely last the lifetime of the water heater because condensation can result in rust which causes them to malfunction. A malfunctioning flow sensor will not send the right signals to the control board making it think that there isn’t any water flowing through.

The control board then shuts down the flame in the unit for safety reasons.

Below are the steps to replace a Malfunctioning flow sensor

  1. Start by Opening up the front panel of your water heater and locating the flow sensor. Clean it well with a dry cloth. Restart the water heater. If the unti does not begin heating again, it means you need to replace the sensor.
  2. To replace the sensor, Make sure that water is shut off to the unit and it is powered down at the control panel
  3. Unscrew the flow sensor from the control board and replace it with a new one. You can find the right sensor you need in your manual
  4. Power the unit back up and wait for 30 minute to see if the unit starts heating again.

Control Board Is Malfunctioning

If you notice your Navien’s control board is malfunctioning (for example, it’s not displaying at all, the device is not properly functioning, etc.) then it is likely the control board that needs to be replaced.

The control board serves as the brain on the unit. It decides when to turn on and off different components including water flow and temperature changes based on the signals fed to it by the different sensors on the unit.

Before you replace the control board, you should try resetting the device first. I’ve found that sometimes the unit encounters errors that prevent the control board from doing its job. If this does not return the unit back to working condition, then you will need to replace the board.

This is one of those jobs that I think is best handled by a professional. But if you chose to handle it yourself, Here are the steps to do so.

  1. Shutoff water and power to the unit. I usually shut off to the unit at the circuit breaker
  2. Open the front of the unit and carefully detach all wires and sensors from the control board
  3. Loosen the control board from its harness by unscrewing it from the back of the panel
  4. Pull out the control board and replace with a new one
  5. Re-attach all wires and sensors to the control board
  6. Close the panel, turn on water and power

Bad Heat Exchanger 

Your heat exchanger serves a crucial function on your water heater, and allows the heat from the gas to transfer (or “exchange”) to water without coming in direct contact. Issues with the heat exchanger can cause a multitude of issues, including water that doesn’t reach the proper temperature. If you think this might be an issue, you should contact a professional. Because this issue involves potentially hazardous gas, it’s not recommended that you handle it on your own.

Water Not Heating 

I’ve found that troubleshooting the “No Hot Water” problem can be really easy or difficult. The problem could be caused by any of the following problems

  1. No power to the unit. This is the first thing I always check
  2. No water flow into the Unit. Without water flow, the control board will not activate the flame to heat the water
  3. A bad Control Board
  4. A bad Flow sensor
  5. A Defective Thermostat

As mentioned above, a heat exchanger can cause issues with water temperature, but this can happen for many other reasons as well. It might be an issue with the device’s internal thermometer, or it might be that you have improperly set the temperature on your device. Whatever the case, unless you’re an expert in this area, you’ll have difficulty identifying and solving this problem without the help of a professional.

And More: Although these are the most common issues experienced by Navien device users, there are many more possible issues. The best thing to do if you encounter an unknown issue is to call a professional.

Related Posts:

How do I Reset My Navien Tankless Water Heater?

First of all, as is the case with many home appliance issues, it’s often the case that a simple reset will solve your problems. If you encounter an issue with the water heater that you perceive as minor, or you’re seeing an error code on the device that you don’t understand, it’s often the case that a reset will fix the issue, or is at least worth a try.

Unlike some other devices, Navien makes it extremely easy to reset its tankless heater. It might differ slightly depending on the model, but most Navien units have a reset button affixed to the front control panel, which is usually located below the main power button.

Hold the reset button, wait about two minutes, turn the device back on, and see if this has fixed your tankless water heater problem. If not, check out our troubleshooting guide

Troubleshooting Your Navien Tankless Water Heater

The Navien tankless water heater has a few known issues that are frequently experienced by users. Common issues often center around a lack of hot water, poor water flow, the control board, the heat exchanger, and more. In our guide, we’ll show you how to identify these issues and what to do about them.

What is Navien Tankless Water Heater?

A Tankless water heater is a very handy device. Its ability to give you hot water without occupying ample space in your home is extremely useful for many users. And Navien has established a reputation as one of the best in the business, thanks to a high-quality water heater that usually works just as intended. If you notice an issue with your Navien water heater, there is one crucial first step you’ll want to take.

Navien Tankless Water Heater Error Codes

In reality, there are many more issues which could potentially affect a Navien water heater, just as is the case with any water heater. Often, you’ll be able to identify the problem based on an error code which may be displayed on the device. You can check out a comprehensive list of error codes here.

Call a Professional

We know, we sound like a broken record at this point. But this is the most important point we will make this article. Many of the issues in this article are highly technical and complex. Even with an error code, you may be unsure how to approach the situation, unless you’re an expert in water heaters. For this reason, you’re advised to contact a professional to address the situation.

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