How to Flush a Water Heater

This site contains affiliate links to products. We may receive a commission for purchases made through these links.

Household chores might not be fun, but if you don’t stay on top of them, things tend to get out of control quickly.

This applies to tasks like flushing your water heater, tasks that are easy to overlook because you don’t need to do them every day. However, it’s important to remember to flush your water heater from time to time to ensure that it’s more efficient.

But if you’ve never done it before, you might wonder how to flush a water heater. It’s a straightforward task, but it’s vital to do things in a specific order.

Why You Should Flush the Water Heater?

Before going into the details, let’s explain why flushing your water heater is necessary. First of all, you no doubt like having hot water in your home, and regular flushing of the water heater will help to ensure it stays that way.

Without flushing, your water heater will develop sediment buildup over time. This will then lead to clogging of your water lines and will inevitably decrease the function of the heater itself.

How Often Do You Need to Flush the Water Heater?

The answer to this question will depend on how old the water heater is. The longer you’ve had it, the more often you’ll need to flush it.

But on average, you can do it every one to three years. And given that the task isn’t overly complicated, you might as well do it yearly so there’s never any sediment accumulation.

Things You’ll Need for the Job

When you’re ready to start, be sure to have all the essential tools on hand. These will include:

  • Wrench
  • Towels
  • Hose

These are the tools you’ll need if you have a way to safely direct the hot water from the heater. If that’s not the case, you’ll also need a few buckets for the large volumes of water involved.

You can discharge the water in your garden, for example, but make sure it cools down first.

Important Note: It’s crucial that you check the warranty of your water heater. Even the smallest repairs render it void. So, only proceed if it has expired.

Flushing the Water Heater – Step by Step Guide

After you’ve checked the warranty and have gathered all the items required to perform the task, it’s time to get down to business.

1. Turn Off Water and Power

Whenever you have water and electricity in combination, safety is of paramount importance. Prior to touching anything on the water heater, you’ll need to disconnect its power source.

On the main breaker panel, turn off the circuit breaker. But also unplug the heater altogether.

However, if you’re using a gas water heater, turn the heater to “Pilot” settings. If the power source isn’t completely off, it’s not only dangerous, but it can also be damaged by water.

Now, onto the water supply. Turn off the cold water valve. You’ll locate it either above the water heater or on top of it.

2. Run the Hot Water

Ideally, you would give it a day before moving on to Step 2 because that’s enough time for any hot water in the heater to cool off. This way you’ve avoiding any potential burns.

But if you’re sure you can manage, you can proceed. What you need to do is run the hot water from any other tap in your home. This simple trick will prevent the creation of a vacuum while the tank is draining.

3. Attach the Hose

If you have your hose ready, it’s time to find the drain valve. It looks like a faucet and it’s usually at the bottom of the heater. All the water that’s going to come out needs to be discharged somewhere.

Therefore, connect the hose to the valve and make sure that it’s not loose. You can use the wrench if the faucet is stuck. Finally, place the other end of the hose into a draining source, or use the bucket system.

How to Flush a Water Heater

4. The Drainage

There will likely be a lot of spraying and splashing around. That’s why it’s best to do this when the water isn’t as hot. If you’re using buckets, you can shut the valve off while reaching for another one or emptying the current bucket.

While the water is released from the water heater, you’ll be able to see all the sediment and the dirt pour out. It’s important to leave the valve open until everything discharges and the water heater is empty.

5. The Flushing

After all the dirty water and sediment is out of the tank, it’s time to flush the heater.

If you want to know how to flush a water heater properly just remember that it’s best to do it in stages. Open the cold water valve for a short period and let the water in.

Then let it drain again, so all the residue of the dirt will discharge. Repeat this process as many times as you deem necessary. But once you notice that the water coming out is clear again, that’s a good sign that the job is done.

6. Refill the Water Heater

Now it’s time to do everything in reverse. You should remove the hose, close the drain valve, and prepare to refill the water heater. Also, you can open all the hot water taps in your home again to avoid the vacuum issue.

Then proceed to turn the cold water back on and allow the tank to fill. Finally, when you notice that the water flow in all the open taps is uninterrupted, you can turn them off.

7. Turn the Power Back On

If you have an electric water heater, make sure to plug it back in and restore the previous setting on the circuit breaker. If you have a gas tank, you’ll need to relight the pilot and move back the temperature dial to where it was.

In no time, you’ll be able to hear the water heater doing what it’s supposed to. To confirm, test the water after an hour. And that’s about all there is to it.

It probably sounds more complicated than it is in reality. But after you do it a few times, you’ll know the process by heart.

If You Have a Tankless Water Heater

There are many reasons why some people prefer to use a tankless water heater. It will warm your water on demand instead of keeping it in a tank.

But that’s why they’re usually more expensive to purchase as well as maintain. Also, they do need yearly flushing to avoid calcium buildup and hard water.

Here are the most important steps on how to flush a water heater that doesn’t have a tank and runs on gas.

  1. Turn off the power source of the heater. And make sure that it’s off by using a non-contact voltage tester.
  2. Close the both hot and cold water valves.
  3. Connect one end of a hose to the cold water valve and the other to a Submersible pump.
  4. Then put the pump in a bucket.
  5. Use another hose to connect it to hot water valve and put it in a bucket too.
  6. Now, make sure that you pour a high-quality white vinegar into the bucket. But don’t dilute the vinegar with water or any other liquid. And never use any chemicals either.
  7. Open the hot and cold water valves.
  8. Turn on the pump too and let the vinegar circulate for about an hour. This process will remove any problematic build-up in the pump.
  9. Remove the pump, turn it off, and pour out the vinegar.
  10. Once you disconnect the hoses, it’s a good idea to let the cold water rinse the pump for about 15-20 minutes.

A tankless water heater that runs on electricity will have a similar flushing method. You’ll also need quality white vinegar and water.

But it will take a lot less work, and instead of placing the pump in the bucket, you’ll pour the vinegar in the heater’s chambers.

Time-wise, they’ll both take around an hour for flushing, but electrical tankless water heater is definitely more convenient.

Cleaning the Filter

With both gas and electrical water heaters, it’s advisable to clean the inlet filter to ensure better performance.

Disconnect the cold water filter and flush it with some lukewarm tap water. That will get rid of any sediment that has accumulated over time. Then place it back and open the cold water valve.

Final Thoughts

Now you know all the steps needed to flush a water heater — tankless or standard. There’s nothing too complex, but you might need a little practice to do it with finesse.

Fortunately, it’s not the type of thing you’ll have to undertake very often, because it can get messy. And to reiterate, always check the status of the water heater warranty before touching anything.

Whatever you do, make sure that the power source is always turned off and that you have all the safety protections in place. If you’re not sure you can flush the tank on your own, or don’t have the right tools, call an expert.

Leave a Comment

Your email address will not be published. Required fields are marked *

Special offer for our visitors

Get your "Living a Stylish Life" Free Guide

We will never send you spam. By signing up for this you agree with our privacy policy and to receive regular updates via email in regards to industry news and promotions