How to Flush Your Tankless Water Heater

It is expected that you should regularly flush the water heater to ensure optimum performance and efficiency of the unit. This will help extend the service life of the water heater as well as reduce fuel expenses. As the unit is used over time, it accumulates mineral deposits which can erode the walls inside the chamber to drastically reduce its efficiency.

Although the flushing task is not difficult, if you don’t have the time to follow the recommended steps in this article, you can call a professional from Just Water Heaters to get a perfect water heater maintenance service.

For those who have the time and are technically savvy; get a cup of coffee, relax and read this article to know the right steps to take in flushing your tankless water heater.

The following tools are essential to complete this simple task, that will help your unit run at peak performance:

  • A submersible pump
  • A bucket
  • Needle nose pliers
  • Screwdrivers
  • Two stainless steel washing machine hoses
  • Non-contact voltage tester
  • Four gallons of white food grade vinegar

Flushing procedure for gas-fueled tankless water heaters

Step 1 – safety procedures

Shut off the main gas supply to the water heater and turn off your electric power source

Turn off the three water valves that are responsible for inflow of cold water and outflow of hot water. The cold water valve is colored blue, and the color of the hot water valve is red. They need to be shut off to avoid inflow of cold water when the flushing is going on.

You need to relieve any pressure that has built inside the valves by gradually opening the hot water relieve valve.

Step 2 – hose connection

There should be hosing lines that are provided by the manufacturer of the water heater, if they are not available, get from a home repair store nearest to you.

Fix the first hose at the cold water service port and the second to the service port meant for cold water. The other end of the first hose should be connected to the submersible pump and the unattached end of the second hose into a bucket.

Remember, the submersible pump should be placed in a 5-gallon bucket filled with virgin, food grade, white vinegar.

Step 3 –flush the water heater

Open the hot and cold service ports and turn on the submersible pump so that the vinegar will circulate through the tankless water heater.

Turn the submersible pump off after an hour and dispose of the vinegar.

If there is lime scale build up in your water heater, it will be flushed for the unit to continue working efficiently.

Step 4 – rinsing

To avoid health complications, you need to rinse the water heater because your homes drinking water flows through it.

Place the unattached end of the hose and place it in a drain outside your home. The hot water shut-off valve should not be opened to allow cold water to pass through cold water service ports.

Allow water to flow through the unit for about 10 – 20 minutes to ensure that the vinegar is flushed out completely.

You can check out your manufacturers’ manual for further instructions. Call a professional at Just Water Heaters if you’re overwhelmed by this recommended flushing procedure.