Navien Hot Water Heater Troubleshooting

• Check if the water inlet filter is clean.
• Check if there is an error code displayed on the front panel.
• Check of the water heater is frozen.

If there is an error code on the front panel, refer to your manual to check what the code is referring to. But if there is no error code, make sure that the shut-off valves on the hot and cold pipes are open.

When Water From The Hot Water Faucet Is Cold Or Turns Cold And Stays Cold

Check for the following when this happens:

• Check if the water inlet filter is clean.
• Check if the hot water faucet is open wide enough.
• Check if there is an error code on the front panel.
• Check the external recirculation system (if availble) to see if there is a check valve on the recirculation return line.

Here are some solutions you can try:

• If the cold water inlet filter seems dirty, you should clean it. You can refer to the manual for the proper way of cleaning it.
• Try opening the hot water faucet completely.
• Refer to your manual if there is an error code displayed on the front panel.

When It Takes Too Long For Hot Water To Reach The Fixtures

If you are using the external recirculation mode, have a contractor come in to install a recirculation return line from the faucet that is the furthest back from the water heater.

When The Water Is Not Hot Enough

Try to check if the temperature is set too low. Another thing you can do is check for cross plumbing between the cold and hot water lines.

When The Water Is Too Hot

Try to see if you’ve set the temperature too high.

Other Minor Problems

If minor problems occur, try to reset the water heater. Doing that solves the issue most of the time. You can reset your water heater by pressing the Reset button located on the front panel.

However, if resetting the water heater and trying the solutions listed here doesn’t work, then it’s best to call in an authorized technician for assistance.

Additional Notes

Making sure your water heater is maintained regularly also helps prevent problems. So make sure to clean your heater regularly and also drain the heater before doing maintenance tasks.