How to Drain a Water Heater the Right Way

Water heater dripping water

Your Guide to Draining a Hot Water Heater

Your hot water tank is meant to hold water for years and years, but regularly draining your tank is an important part of home maintenance. Once you learn how to drain a water heater, you’ll see that this task is quick and simple!

Step 1: Know When to Drain the Tank

The first thing you need to be aware of is when you should be draining your water heater tank. You can often check your user manual to get instructions on the exact timing for tank draining. According to, most tanks should be drained at least once a year.

Draining a tank helps to clear out sediment that settles at the bottom of the tank. Sediment is a problem because it can reduce the quality and cleanliness of your hot water, and it also makes it harder for your tank to heat water. If sediment does get pulled into your pipes, it can cause buildup that requires repairs to unclog pipes. Therefore, draining a tank helps lower your energy bills and improve the quality of your hot water.

Step 2: Turn Off Your Heater and Water Connection

Safety first: All of the following steps for draining a water heater should be done with the power turned off. For electric tanks, just flip the switch. If you have a gas tank, turn your heater to pilot mode. It is safer to let the water cool before proceeding. You can take a hot shower or just turn on hot water faucets to go ahead and remove some of the hot water.

Afterwards, locate the cold water supply. Turn the knob or trip the lever to turn off the water. With the water and power off, you can safely proceed to the next steps.

Step 3: Run the Drain Line to a Good Draining Location

Unless your tank is outside and in a well-drained location, you will need to attach a drain line. This can be as simple as twisting a garden hose onto the drain and running it outside. If your tank is at a low level, like in your basement, you may need to attach the hose to a pump. This can help counteract gravity and push the extra water away. Anywhere that connects to a drainage point, like a shower floor drain or a cleanout, is a good spot for the end of the hose.

Step 4: Quick Flush Your Drain and Check Your Pressure Relief Valve

Before flushing the drain itself, check to make sure the pressure relief valve is working. This step is not necessary, but it also needs to be done regularly. If you notice any issues with your water heater or pressure relief valve, you may need to check this valve sooner than scheduled. Combining these jobs will let you get two maintenance tasks out of the way at once.

Place a bucket under the valve and pull up the lever on the top of the valve. You should hear air hiss or water expel through the overflow tube. If nothing comes out, you may need to replace the valve. Next, move on to the drain valve. Open it for a few seconds and then close it. Repeat this a couple times. This high-pressure burst can help push any sediment through the drain valve so the tank drains quicker.

Step 5: Open Your Drain Valve

Once your garden hose is positioned in a spot where you can dump a lot of water, proceed with opening the drain valve. If you notice water is leaking out very slowly, you most likely have a vacuum forming in your pipes. You can turn on a hot water faucet somewhere else in your home, like the bath tub, to break the vacuum. This will let water flow out more quickly.

Step 6: Flush the Tank

Next, it is time to use some fresh cold water to flush any remaining sediment out of your tank. While leaving the power to the tank off, turn on the cold water for a few seconds. Give it just enough time for a few gallons to flow into the tank, then turn off the water again. Run cold water through and let it drain a few times to finish flushing your tank. These short bursts of high-pressure water will break up the sediment clumps still in your tank. When the water starts running clear, you can move on to the next step of how to drain a water heater.

If you’re having trouble with this step, consider contacting a professional. They may recommend a hot water heater replacement.

Step 7: Refill the Tank and Turn It Back On

Now you can refill your water heater fully. Remove the hose on your drain and close the drain valve. If you had any hot water faucets on in your home, you can turn them off now as well. Turn on the cold water supply and leave it on to fill up your tank. Restore power to the tank so it can start warming your water again. If the pilot light went out on your hot water heater, you may need to relight it before it will start warming your water again.

Step 8: Check Both Valves for a Tight Seal

The final step of draining a tank is making sure all the valves you adjusted are back to their initial, leakproof positions. If you left your pressure relief valve on, go ahead and turn it back to its original position now. There is a small chance that an older, plastic drain valve may not be able to close again completely. If this happens, you might notice a slow, steady drip from the valve. You can put a cap on it to stop any drips for now or get a plumber to replace it with a sturdier valve.

In case anything goes wrong, be prepared with a plan from Service Lines Warranties of America . Our plans can assist with the stress and associated costs of hot water heater repairs. Once you have a plan in place and a plumbing issue arises, you can call our 24/7 repair hotline and schedule an appointment with HomeServe’s network of plumbing technicians. We assist with the cost of repairs so you can protect your finances. Learn more about  how plans from Service Lines Warranties of America can help with the costs of home repairs.

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