How to Properly Flush a Gas Hot Water Heater

Sediment can build at the bottom of your gas water heater's tank.

Hot water supplied from your gas water heater aids home activities such as cooking, cleaning and bathing. But minerals in water can accumulate in your hot water heater's tank. As the mineral deposits build, so does a layer of sediment at the bottom of the tank. If the sediment grows high enough, it can interfere with the efficiency of the heater by affecting the lower heating element. Sediment buildup can also cause poor water quality. You can prevent these negative effects by flushing your gas hot water heater.

Things You'll Need

• Garden hose
• Bucket

Instructions

1. Turn the water heater's shutoff valve to stop the gas supply.

2. Shut off the main gas line to the water heater.

3. Turn off the cold water supply to the heater's tank.

4. Connect a garden hose to the drain valve at the bottom of the tank.

5. Run the unconnected end of the garden hose to a drain or outside of your home. You may also place the end into a hard plastic bucket.

6. Open a faucet within your home. Turn the faucet to the "hot" side.

7. Open the drain valve on the hot water heater.

8. Allow the tank to drain completely. If you are draining into a bucket, monitor the water level and empty the bucket as needed. Turn off the drain valve before removing the hose from the bucket.

9. Turn off the drain valve.

10. Turn on the cold water supply and allow the tank to partially fill.

11. Open the drain valve.

12. Turn off the cold water supply.

13. Allow the tank to completely drain.

14. Turn off the drain valve and disconnect the garden hose.

15. Turn on the cold water supply and allow the tank to fill. The tank is full once water comes out of the faucet you opened.

16. Turn off the faucet.

17. Turn the gas back on to the main supply line and water heater.

Tips & Warnings

• Use a thick garden hose to avoid the material becoming soft and leaking when draining hot water from the heater's tank.

• If the drain valve clogs during the flushing process, turn on the cold water supply while draining the tank.

• Do not turn off your gas water heater unless you know how to reignite it.

• Use caution when draining the tank, as the water may be very hot and can burn you.

References

• Natural Handyman: Draining the Sediment from Your Hot Water Heater