How to Flush a Water Heater

Water heaters can last for much longer than you originally anticipated, especially when you take the steps necessary for proper maintenance. While there are many different ways to extend the life of your water heater, one of the best ways to make sure you flush your water heater once every three years. When you flush your water heater you control the build up of mineral deposits, and keep the heater working properly. Here are instructions on how to flush your water heater for all you DIYers.

Step 1: Turn your heater off

Before you drain your water heater, it’s important to locate the breaker or fuse box and turn it off. Once you locate the breaker box, or the thermostat for a gas heater, simply switch it off. Usually, it will have three settings including “pilot,” “on,” and “off.”

Step 2: Turn off your cold water supply

The next step is to turn off your cold water supply by turning the water shut-off valve clock-wise.

If you have a ball valve, one 90-degree turn should do the trick. If you have a gate valve, you will need to turn the knob several times before it reaches “stop” and is fully closed. Also, take note that if you have a natural gas and propane tank, you will need to set the thermostat to the lowest setting, or “pilot.”

Step 3: Open the hot water faucet in your tub or sink

This is another precaution that will help prevent a vacuum effect in your lines.

Step 4: Attach a garden hose to the drain cock or valve located on the water heater

This drain cock will generally look like a regular garden bib and may be hidden under a cover. If you have trouble locating it, consult your owners manual, or contact us at Absolute Precision Plumbing today for more info.

Step 5: Run the hose to a safe place for drainage

Some of the best places to extend the other end of the hose are on the lawn or in a big bucket in the garage. This way, you don’t risk any potential water damage to your home.

Step 6: Open the drain cock or valve

Once you have attached the hose and extended the hose to a safe place for drainage, it’s time to open the drain cock or valve and begin the draining process. You will want to make sure the pressure valve is in the up position, and that the water flows smoothly and slowly.

Step 7: Fill another bucket to test the drainage process

Fill another bucket and allow it to sit undisturbed for a minute. Check to see if the water is clear, or murky. If the water is still murky, or if you see sediment collecting on the bottom, continue draining the water heater until the bucket is clear.

Step 8: Close the drain cock and remove the hose

Once the water in the bucket is clear, you can close the drain cock, remove the hose, close the pressure-valve if it’s still open, and turn off the hot water faucet in your sink and/or tub.

Step 9: Turn the water supply back on and refill the tank

You are finally ready to refill your newly cleaned tank, and equalize the pressure. To do this, slowly reopen the pressure-relief valve to get rid of any excess air.

Step 10: Close the water heater drain

Before you turn on the power, open the hot water tap in the bathroom. This will also help get rid of any excess air. Wait until the water is streaming fully and normally. 

Step 11: Turn the water supply back on

Once the hot water is up and running, you are ready to turn your circuit breaker or fuse box back on.

Step 12: Turn off the tub spigot

The last step is to test your work. Wait for about 20 minutes and then test to see if hot water is running. Make sure to listen carefully to your water heater, and enjoy your results.

The information contained in this blog is for general information purposes only if you are not comfortable following these steps on your own, or simply don’t have the time, please feel free to call one of us at Absolute Precision Plumbing & Heating, and we will do it for you. We would love to hear from you and would love to be of assistance in any way we can.