How to Flush a Hot Water Heater

 Hot water heaters should be flushed at least once a year – especially, if your area is under construction – to control the build-up of mineral deposits.  This will help the hot water heater operate more efficiently and will usually extend its life.  The hot water heater will also need to be flushed if the hot water becomes a yellow or brownish color due to an accumulation of rust or if you find sand-like mineral sediment in the hot water.  The procedure for flushing your hot water heater is outlined in the following steps.  NOTE:  Shut off the power to the hot water heater to avoid burning out the probe. 

1.                 Close the cold water valve above the hot water heater to prevent more cold water form entering the tank.

2.                 Use as much of the existing hot water in the tank as you can until the water turns yellow to avoid wasting the water.

3.                 Attach a garden hose to the draincock located at the bottom of the heater.  The draincock usually looks like a regular hose bib (garden faucet) or a round dial with a threaded hole in the middle.

4.                 Extend the garden hose to a place where the water can safely exit the heater (e.g. a drain, a driveway, etc.).

5.                 Open the draincock to allow the water to exit the heater.Caution:  The water leaving the heater will be hot.  Also note that if the draincock is made of plastic and the heater is several years old, it may be difficult to open and may break easily if forced.

6.                 When the tank is empty, close the draincock and open the cold water inlet valve above the heater to let in about 2 gallons of water (30 to 60 seconds worth)

7.                 Open the draincock and drain out the 2 gallons you just added.  Repeat steps 6 & 7 until the water runs clean.

8.                 Close the draincock, remove the garden hose, turn the power back on and open the cold water inlet valve above the heater. If you do not feel comfortable doing this work yourself, hire a licensed plumber to do it for you.