How To Reset A Tankless Water Heater [4 Easy Steps]

Ben Leonavicius
By Ben  • Updated:   February 9, 2024
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Tankless water heaters are designed to provide an endless flow of hot water. But if there is a power outage or some other event that causes the unit to lose energy, how do you get it back up and running? And what to do if your tankless water heater is not heating up?

You may have heard that tankless units don’t have a pilot light like your standard water heater. 

The good news is, your tankless water heater does have a reset button that will power up the unit once more. These step-by-step instructions will show how to reset your tankless water heater.

How to reset a tankless water heater: 4 quick steps

Step 1: Locate the tankless water heater reset button

The location of the tankless water heater reset button can vary depending on the make and model of your water heater. For tankless models, it’s typically located on the side or front of the unit, but you should check your owner’s manual to confirm.

If you can’t find it after a few minutes of searching, call the customer service number of your water heater provider.

Step 2: Verify that the tankless water heater reset button is in “Reset” mode

In order to start up the heating process again, you’ll need to put the reset button into “reset” mode by pressing it once more.

The light will turn from red to green when done correctly. Once it does this, wait ten seconds before proceeding further. 

Afterward, if there’s still no power going to the unit, call a professional because your tankless water heater may have a larger issue.

Step 3: Turn the thermostat up

There is typically a knob on your tankless water heater that allows you to increase the temperature of the unit. Turn this knob clockwise until it’s at its highest setting, which will allow the unit to reach maximum capacity once more. 

Once again, wait ten seconds before turning anything else on or using any appliances that require hot water. 

Doing so immediately can cause issues with how well your tankless system works in the future and can lead to other problems in your home.

Step 4: Check for a power outage in the house

The problem is likely not with how well your tankless system works but how well your entire home electricity system is operating. 

Some external reason, such as a downed power line on the street outside your house, or an issue with how well your electricity is supplied, has made you lose energy in your entire home rather than just your tankless water heater.

So how do you fix this? Turn on a breaker.

For most people, the issue is how the breakers have been turned off. 

To restore power throughout your house, you’ll need to turn each of them back on. It doesn’t matter which breaker you choose as long as the tankless water heater switch is flipped back on and can be accessed easily in case there’s another outage in the future. 

Afterward, turn on the heat again and wait for it to come back.

Still Not Receiving Power From Your Tankless System?

If you’re still not receiving power from your tankless system despite following these steps exactly, call a professional because this likely isn’t an isolated incident but part of a larger problem.

I hope that was helpful!

Although this blog post was specifically about how to reset a tankless water heater, these steps can also be used to reset any water heater in your home, whether tankless or immersion. Check out some other useful tips for home appliance maintenance!

Hey there! I am Benas, the founder and content editor at Home Caprice. Thanks for reading the article. I hope you were able to find what you were looking for. I and my team are here to simplify heating and cooling for everyone. Please have a look at the About page for more details about our website and feel free to check out our editorial process.