How to Drain & Flush Your Water Heater

over 3,000 reviews

Flushing your water heater is an essential part of maintaining your appliance. Read on to learn the benefits and steps to complete this task yourself this season.

Do I need to flush my water heater?

Short answer: Yes. Flushing your water heater prevents buildup from minerals such as magnesium, calcium, and limescale. If you don’t flush your water heater, these minerals can accumulate on the heating element and interfere with its efficiency and lifespan. In extreme situations, it can even cause your water heater to fail completely.

When do I need to flush my water heater?

Flushing your water heater once every year is the typical recommendation for most areas. If you live somewhere with extreme water hardness, flushing the tank every six months will keep sediment from accumulating too heavily.

How do I flush my water heater?

Our plumbing pros share nine easy steps to flushing your water heater:

1. Turn off the cold water supply

Locate the water supply shut-off. This is usually found where the main water supply line enters your home. If you have a water softener, you can also use the supply shut-off valve there.

2. Turn off your water heater’s thermostat

Turning the thermostat off prevents the appliance from turning on and trying to heat water as you’re working on it. This step is essential: if the heating element turns on after the water has drained out, it can damage the tank. For homes with gas-powered appliances, be sure to close the gas supply before moving on.

3. Connect a drain hose

The drain hose is how we’ll drain water from the tank without flooding your home. Locate the drain valve (likely near the bottom of your water heater’s tank). Connect a hose to this valve and either:

  1. Coil the hose into itself, creating a small circle to catch the released sediment.
  2. Extend the hose out and into a bucket.
  3. Let the water drain outside. If you choose this option, make sure to extend the hose past the foundation of your home — otherwise, you could end up with moisture problems.

4. Open hot water faucets in the house

Opening the faucets helps to create a vacuum, which will make your tank drain more quickly.

5. Drain the tank

Open the water heater drain valve and let gravity do the rest! The water should flow on its own — if it doesn’t, sediment could be clogging the drain valve. Follow these steps to clear it:

  • Open the temperature pressure release
  • Once the water has drained, use a vacuum to remove the blockage from the valve

You don’t have much to do during this step, but stick around and monitor the situation as your water heater drains. Warn small children and keep an eye on pets as the water drains as it can still be hot and could cause scalding.

6. Rinse loose sediment from the tank

Once your water heater is completely drained of sediment, you’ll want to rinse the tank to grab anything that is stuck around the inside. Turn the cold water supply back on (see step 1 above) and let the water run through the tank and out the hose. Let the water run for a few minutes. When the stream runs clear, turn the cold water supply back off.

7. Clearing the drain valve

Disconnect the hose and use a shop vac to remove any sediment in the opening of the drain valve. Sediment buildup in this area prevents a proper seal and can make your water heater tank leak. When the drain valve is cleared, close it up and turn the cold water supply back on.

8. Clear all faucets

As your tank fills with water, leave the faucets open. You can close them again once the water begins to flow out — this step prevents air from becoming trapped and allows any rust or sediment to drain from your plumbing. When the water is running clear, you can move on to the final step.

9. Reset water heater

If you have a gas-powered appliance, reopen the gas supply valve and follow the manufacturer’s recommended process for reigniting the pilot light. For electric appliances, simply turn on and reset your water heater to the desired maximum temperature — most water heaters are set to 140° F, but setting the temperature to 120° F will save energy and reduce the chances of getting burned by hot water. The time it takes to refill the tank varies depending on the size and age of your system, but the standard water heater tank should refill in 30 – 40 minutes.

Congratulations! You’ve successfully flushed your water heater. This task is simple enough in theory, but if you run into any problems or would be more comfortable hiring professionals to take care of this task for you, give Steve’s Plumbing & A/C Service (808) 563-4054. a call! (808) 563-4054

What Our Clients Say

Matt was very professional and considerate as we are in a COVID world. May not necessarily be the cheapest but you are paying for the quality, peace of mind, and quick response time to my urgent matter. I will definitely call them again for my next plumbing issue.

-Elias S.

If you have any plumbing needs this is the company to use. They said they would be there at 9:30 and by gosh, they showed up at 9:28 that not a normal thing when it comes to plumbing. Both of them were not they answered all my questions without hesitation and got the job done within 45 minutes even though they said it would take an hour and a half.

-Bob J.

Brayden and Maka worked on a major repair at our home over a time period of four days. We have high praise for both of them, their professionalism, courtesy, friendliness, and reliability. Steve’s Plumbing is lucky to have these two fine employees.


Shon Bolo was very courteous. He was very informative about how Plumbing is just as important as the engine of a car. He was very respectful. Even though I wasn’t able to get everything done as expected. Shon was able to install my laundry tub to get my washer ready to drain and connected. Definitely would recommend shon bolo to friends and neighbors. Thank you very much for the wonderful job. Great service Shon!!

-Rowena H.

Want to learn more about heating and cooling?
We’ve got you covered.
Clogged overflowing toilet bowl Common Reasons Your Toilet Won’t Flush We’ve all been there – you go to flush the toilet, but instead of that satisfying swirl of water, you’re left staring at an unmoving...
Kitchen Why Is My Dishwasher Backed Up With Water? There’s nothing more disappointing than going to unload your dishwasher only to find the tub pooled with murky water. A backed-up dishwasher is an unwelcome...
Bathroom Why Does My Toilet Whistle When Flushed? Hearing an unexpected whistle coming from your toilet can certainly be a head-scratching moment. You flush, and instead of the normal whooshing sound, your commode...