How to Flush Your Water Heater

Each year after the spring water main flushing program has been completed, we suggest residents flush their hot water heaters. Many types of sediment such as iron, magnesium and calcium may build up in the bottom of your hot water heater, causing discoloration or rust in the hot water taps. (Calcium appears as sand particles in the hot water system.) In most cases, flushing the hot water heaters can eliminate this. Listed below is a simple procedure you can follow to flush your hot water heater:

  1. Turn the water off at the water meter.
  2. Turn gas heaters down to “pilot” or electric heaters to the “off” position.
  3. Hook up a water hose to the tank drain outlet at the bottom of the water heater and place the other end of the hose by the floor drain.
  4. Open a hot water tap at the laundry tub to allow air into the hot water pipes.
  5. Open the hot water heater faucet and allow tank to drain completely.
  6. Once the tank has drained, turn the water back on by the meter. Let the tank fill until the water begins flowing out of the hose at the drain.
  7. Allow the water to flow through the tank for 2 to 3 minutes, then shut the water off at the meter and allow the tank to drain out completely once again.
  8. Repeat steps 6 and 7 until water flows clean at the drain.
  9. Once the water flows clean again, shut the drain faucet off at the bottom of the hot water tank and remove the hose.
  10. Turn the gas or electric heater controls back to the “normal” or “on” positions. Also be sure to turn the water back on at the meter to allow refilling of the tank and proper operation of your water system throughout your residence.
  11. Open all hot water taps throughout the residence to flush out all sedimentation that may have become agitated throughout the hot water pipes during the tank flushing. Close all taps as the water flow clears.
By following these steps, not only will the hot water tank be cleaned out, but also the heater will run more efficiently and help conserve energy.