DIY guideWater heater
Flush a water heater
Drain the sediment out of a tank water heater, with every safety step in order.
- 45 min to 1½ hr
- 6 steps
- Every step animated
6 steps
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Electric: switch off the water heater's breaker. Gas: turn the control knob to Pilot or Vacation. Then let the water cool for a few hours.
The water inside can scald. Let it cool first.Turn the cold water valve on the pipe at the top of the heater clockwise until it stops.
Screw a garden hose onto the drain valve near the bottom and run the other end to a floor drain or outside, lower than the valve.
Open a hot water tap upstairs to let air in, then open the drain valve. Let it run until the water comes out clear.
Close the drain valve and take off the hose. Open the cold water valve and leave the hot tap running until water flows with no sputtering, then close the tap.
Only once the tank is full: switch the breaker back on, or turn the gas knob back to its setting.
Never turn an electric heater on while the tank is empty. If you smell gas, leave the house and call your gas utility from outside.
What you need
- A garden hose that reaches a floor drain or outside
- A bucket
- Work gloves
Call a pro if
- The drain valve won't open, or leaks once it's closed
- The tank is old and has never been flushed
- You smell gas, or the pilot light goes out
- Water is pooling under the tank
Free for every home. Handyman asks a few questions, then books a pro it trusts.
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