How do I flush a water heater?
Water heaters should be flushed at least once a year - twice a year is even better - to control the build-up of mineral deposits. The water heater will operate more fuel efficiently and will last longer.
The water heater will also need to be flushed if the hot water becomes yellow or brown due to an accumulation of rust or if you find sand-like mineral sediment in the hot water.

If you do not feel comfortable doing this work yourself, hire a licensed plumber to do it for you.

1. Do not shut off the gas or the water supply to the heater.

2. 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.

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

4. Open the draincock to allow the water to exit the heater. Caution: the water leaving the heater will be hot and under normal household water pressure. 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.

5. After five minutes of flushing, fill a bucket with the still flushing water.

6. Allow the water in the bucket to stand undisturbed for a minute and see if the water has cleared or if any sand-like material settles to the bottom. If the water has cleared and no sand-like material is observed, go on to step 7. If the water is discolored and/or sand-like material is observed at the bottom of the bucket, repeat steps 5 and 6 until the water is completely clear and free of sediment.

7. Close the draincock and remove the garden hose.

Show All Answers

1. How do I shut off my water?
2. How do I disinfect a drain?
3. How do I heat-disinfect my water heater?
4. How do I flush a water heater?
5. I have a leak at my meter. Who is responsible for this repair, me or ACWD?
6. Who can I contact if I have additional questions?