How To Drain Hot Water Heater?

Limescale Heater

Use extreme caution as a hot water heater can scald you in seconds.

  1. To further conserve energy and for safety, flush the hot water heater after bathing, washing clothes, or cleaning dishes when less hot water is in the tank.
  2. Turn the water heater temperature control to low to prevent the gas burner from lighting. Even better turn off gas, then relight when done. Electric water heater? Make sure you turn off the power before draining. If you don’t you could destroy the heating elements.
  3. Option one: Open the drain at the bottom of heater twice a year, letting the water run into a bucket (usually about 5 gallons). Prevents hard water sediment accumulation. (Good reason to have a water softener that removes hard water minerals).
  4. Option two: connect garden hose to water heater drain and run outside. You could empty into a floor or sink drain but you must know that excessive sediment can clog your drain. Check water quality while draining. Be careful as when you turn off cold water to flush the tank the hose water pressure may move. Secure hose.
  5. Do not drain hot water into a toilet as it may crack or onto your lawn as it will kill the grass.
  6. Kitchen hot water faucet, turn on.
  7. Water heater – turn off cold water supply value (top of heater). Make sure you do not leave gas burner (or electric) on when water valve is closed as it can cause excessive pressure gas pressure to buildup.
  8. Drain heater until little pressure. Turn off kitchen faucet.
  9. Flush tank by turning on-off water heater cold water valve a few times to help clean tank of sediment.
  10. Add water and drain until clean.
  11. Please Note: After many years of experience, sometimes a drain valve that’s never been opened before, especially an old plastic drain valve, will leak when closed. If it does screw on a steel cap with pipe thread to stop water leak.
  12. Tighten heater drain, turn on cold water supply and fill. When water is full turn on gas or electric.
  13. Improve efficiency and water quality with regular flushes

If you don’t feel comfortable with this chore, ask a professional like PDM for help.