How to Maintain Your Tankless Water Heater

How to Maintain Your Tankless Water Heater

If your tankless water heater is not working effectively and you’re wondering how to maintain it, then, this blog article is going to help you.

Tankless water heaters are becoming more popular each year.  One reason is that tankless water heaters are more efficient than traditional water heaters. They use less energy to heat water, which can save you money on your energy bill. They are also environmentally friendly.

Many people have contacted me about how to maintain tankless water heaters, so I’m going to give you my guidance throughout this post.

When it comes to maintaining your tankless water heater, there are a few things that you should keep in mind. One of the most important things to keep in mind is to make sure that your water heater is properly maintained. 

This means that you should check the seals and the vent system regularly, and make sure that there are no debris or blockages in the system. 

You should also make sure that the water heater is properly ventilated. This means that you should make sure that the system has enough ventilation to prevent any build-up of heat. I’ll share with you the procedures you may take to maintain your tankless hot water system.

Supplies You will need to Maintain Your Tankless Water Heater

  • Sump pump: It is also referred to as a submersible utility pump. An ideal descaling power for tankless water heaters is 1/6 horsepower. You should be careful if you are using a pump stronger than 1/4 horsepower.
  • Distilled white vinegar, three gallons.
  • A bucket of five gallons.
  • Two lengths of hose (2 ‒ 4 feet) fitted with the appropriate fittings.

Step-by-step Procedures for Maintaining Your Tankless Water Heater

At the very least once a year, your tankless water heater needs to be cleaned. Calcium deposits are eliminated as a result of this. Consider cleansing your heater more frequently than once a year if your home has experienced issues with hard water. It’s crucial to clean out your tankless water heater if it’s giving you trouble. Here are the steps:

1. Disconnect the power source

Shutting off the power to your water heater is one of the most important steps you can take to avoid a water heater burn. By turning off the power, you are stopping the flow of water and preventing heat buildup.

If your water heater does not have a shutoff switch, there is a good chance that the water heater will explode if you try to turn off the power with a water hose. Instead, you should use a shutoff valve. Shutoff valves are usually located on the side of the water heater.

  • Shut off your home’s main power source.
  • Find the shutoff valve for your water heater.
  • Turn the valve to the “off” position.
  • Double-check to make sure that the power is off to the water heater.

2. Make sure all the water heater valves are closed

All three water valves must be shut off before you can start the maintenance procedure. As a result, neither fresh water nor heated water from the cleaning procedure will be able to enter the tankless water heater. The valves are typically color-coded, with the third valve controlling the water between the main water supply and your residence, while the other two regulate hot and cold water.

3. Remove purge port valve cap 

Purge valves on your tankless water heater aid in reducing pressure buildup. Each of them has a small handle that resembles the letter “t.” To release any pressure that has built up in the purge valves, carefully remove the purge port valve caps. Additionally, this stops hot water from gushing out and perhaps burning you.

4. Connect each valve to the hosing line and open the port valves 

You can buy hosing lines if your tankless water heater didn’t come with any. Connect the water heater to a flushing bucket using the hosing line. To allow the hot and cold water valves to flush through and release water from the tankless water heater unit, you might need to connect the hoses to a sump pump. Consult the manual that came with your tankless water heater model for more detailed instructions.

5. White vinegar or descaling solution should be added to the unit 

Roughly 3 gallons of pure white vinegar or a typical descaling solution can be used to clean your tankless water heater. Since vinegar is natural and typically regarded as safer, many homeowners prefer to use it.

6. The tankless water heater should be flushed and drained 

Once everything is ready, rinse and drain your water heater according to the directions in your manual. You should rinse and drain it into a bucket for around 45 minutes to completely clean it. Close the port valves and unplug the hose after the flushing is complete. After that, gently replace the port caps on the purge valves to reseal them. 

7. Clean the air and water filter in your tankless water heater 

Your tankless water heater’s air filter needs to be cleaned frequently. Remove the filter from the water heater unit and clean it. With a gentle brush and a solution of soap and water. Clean the filter completely to maintain optimal airflow. Before reinstalling the filter in the water heater, give it a thorough rinse and allow it to fully dry.

Also, keep in mind to clean the water filter when doing water heater maintenance. The majority of tankless water heaters have a screen that collects dust. To keep your water heater operating properly, you will need to wipe away these particles periodically. If sediment builds up, your water heater’s ability to perform may be obstructed.

8. Start your tankless water heater up again

Once the flush is complete, shut off the pump and remove the flush hoses. Reconnect the water hoses to the tankless water heater after closing the valves. For the correct start-up procedures, kindly refer to the unit’s user manual. Resuming this process often starts with the gas or power of the appliance being turned on, followed by the water.


You must occasionally give your tankless water heater a thorough cleaning if you want it to continue functioning smoothly and effectively. If you’re handy and have the time, you might be able to accomplish this yourself, but not everyone does. Fortunately, tankless water heater maintenance is something that qualified plumbers can offer to keep it functioning properly.

Problems with your tankless water heater? Want to employ a specialist to perform water heater maintenance? Thompson Plumbing has extensive knowledge of tankless water heaters and can make sure that yours runs efficiently and lasts for twenty or more years.