VIDEO: I Need to Flush My Tankless Water Heater? Yes. Yes, You Do

Bet’cha didn’t know! Just because your water heater is tankless doesn’t mean you don’t have to flush it! Yep, you read that right: If you want your on-demand water heater to keep heating water on-demand, you need to flush it at least once a year.

Related: How Much Does a Tankless Water Heater Cost?

That’s because calcium, minerals and other sediment can build up in the unit over time, causing annoying noises, reducing efficiency, costing you on utility bills and shortening the lifespan of your appliance! But you can ward off water heating woes and forestall an expensive replacement by flushing your tankless water heater at the same interval you’d flush a tank water heater.

For a full demonstration, be sure to watch the video above, in which a bonafide HomeServe technician walks us through the entire process of flushing a tankless water heater. After watching the video, determine for yourself whether you think it’s a “DIY dilemma” or a “problem for the pros,” and let us know what you decided in the comments — and if you learn something there, please like and share!

Here’s the step-by-step process on how to flush and descale a tankless water heater to prevent buildup from hard water:

1. Safety first: Use gloves and goggles.

2. Purchase a water heater flushing kit.

3. Turn off the isolation water valves that connect to your water heater — a blue inlet valve for the cold water and a red outlet valve for the hot water. (A valve is turned off when it’s perpendicular to the pipe.)

4. Connect the hoses to the inlet and outlet valves. (There might be a service port cap on both valves you need to remove before connecting them.)

5. Connect the hoses to the valves and ensure that the hose and valve are watertight, as you don’t want the water to start leaking when you’re in the middle of flushing.

6. Use the circulation pump that came with your water heater flushing kit.

7. Attach the other end of the inlet hose to the circulation pump and place it in the bucket. You only need to attach the inlet hose to the discharge side of the pump.

8. For the outlet hose, you can simply place it in a bucket since the system you have set up will ensure the cleaner goes through the structure and cleans off any magnesium and calcium.

9. Next, add the cleaning agent to the bucket. The bucket should have at least one gallon of water in it before beginning the process.

10. Now, open up the water valves to let water flow through them

11. Start the pump.

12. Let everything circulate for about an hour.

13. Turn off the pump to stop the circulation.

14. Turn off both valves and disconnect the inlet valve hose.

15. Flush out any remaining cleaning agent by keeping the hose connected to the hot water outlet valve and turning on the cold water inlet valve. This will push water up the system and flush out everything through the hose on the hot water side.

16. Let the water flush for 5 to 10 minutes.

17. Turn off the service port and the cold water inlet valve again.

18. Remove the remaining hose.

19. Put everything back the way it was.

20. Plug the service port caps back in.

21. Turn on both water valves.

More Related Articles:

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• How to Flush Your Tankless Water Heater: A 7-Step Guide

• A Tankless Job? Decide Whether a Tankless Water Heater Works For Your Home

• How to Install a Tankless Electric Water Heater: A 10-Step Guide

• What’s the Deal With Self-Cleaning Water Heaters?