Water heater with a hose coming out of it.

How to Flush Your Water Heater

Learn why flushing your water heater annually is a good idea and read our step-by-step instructions to complete this task yourself!

Why do I need to flush my water heater?

Flushing your water heater is an essential maintenance task for any home. All over the United States, water flowing over limestone and minerals such as magnesium and calcium create hard water that can leave sediment in your water heater. This sediment builds up over time and can cause issues that affect the energy efficiency of your water heater and overall lifespan.

How often should I flush my water heater?

It’s recommended that you flush your water heater at least once per year—though if you live in an area with harder water, you may need to flush your water heater more often to help prevent sediment build-up. According to the U.S. Geological Survey, Grand Rapids has very hard water with 380 PPM.

How to Flush a Traditional Water Heater

Follow these steps to flush out your traditional tank water heater:

Step 1: Turn off the cold water supply to your water heater.

You can find the water supply shut off where the main water supply line enters your house or at the supply shut-off valve on your water softener.

Step 2: Turn off the water heater thermostat.

Some water heaters have a “vacation” mode you can use as well. This step is essential to avoid having the heater turn on once all the water is drained out. If the heating element turns on without water to heat, it can damage the tank. If your water heater is powered by gas, close the gas supply valve before continuing.

Step 3: Connect your drain hose.

Find your tank’s drain valve near the bottom of the heater and connect a garden hose. The other end of the hose can coil into itself and create a small circle to catch the sediment, or you can extend it out to a drain or bucket (if you choose to let your water drain outside, make sure to extend the hose past your home’s foundation to prevent flooding in your crawl space.

Step 4: Open all the hot water faucets in your home.

This will help create a vacuum to help your tank drain faster.

Step 5: Open your water heater’s drain valve and start draining your tank.

The water will flow out by itself, but make sure to keep an eye on the stream of water to see how much sediment is in your tank. Keep small children or pets away from the draining water as it could still be fairly hot.

If you’ve opened the drain valve and no water runs out or very little trickles out, you could have sediment clogging the drain valve. If this happens, open the temperature pressure release to release pressure from the tank and drain water that may be sitting in piping downstream from your water heater. After this step is complete, you can use a vacuum to attempt to suck the blockage from your drain valve.

Step 6: Rinse the tank.

Once your water heater’s tank is drained, turn the cold water supply back on to help rinse out any sediment remaining in the bottom of the tank. Let the water run through your tank and hose for a few minutes--check the end of the hose to see when the water runs clear. Turn off the water supply once the water is clear of any sediment.

Step 7: Clear the drain valve.

Disconnect the hose and use a vacuum to suck out any sediment in the opening of the drain valve. This will prevent sediment build-up around the valve, so it doesn’t leak. Once you’ve closed the drain valve, turn the cold water supply back on.

Step 8: Clear the faucets.

Leave the hot water faucets open until water begins flowing out of them to prevent air from becoming trapped. You may see some brown water flowing from your faucets--this is just leftover rust or sediment that will clear out in a few minutes. Once the water clears up, turn your faucets off.

Step 9: Finish up!

Reset the water heater thermostat to your preferred setting (the maximum recommended temperature is 140 degrees, but you can set your temperature to 120 degrees to help save energy and prevent scalds from burning water). If you have a gas water heater, reopen the gas supply valve and relight the pilot using whatever process is recommended by the manufacturer. Your water heater will need time to refill with water--this time will vary, but an average gas water heater takes approximately 30-40 minutes to refill after being drained.

Draining your water heater tank is a DIY task that should be completed at least once a year, but if you’re more comfortable hiring a professional to complete this task for you, contact Grapids Heating & Cooling, Inc.. Our team offers expertise and superior solutions for any water heating needs you may have. Contact us online or give us a call at (616) 223-6777 today!