You’re about to remodel, renovate, fix up, DIY or call a pro, and you’ve got questions! Get answers from design-build expert Mason Hearn, owner of Central Virginia’s HomeMasons.

Jan 22

Something to do on Saturday - Flush your Water Heater

Posted by C. Mason Hearn in water heater, plumbing, maintenance


A plumber was recently at my home to repair our malfunctioning water heater.  He replaced something (a rod?) and everything seems to be fine.  He did tell me that we should FLUSH our water heater more often.  WHAT?  I have never heard of such a thing.  Is this for real??

Rob M., Chesterfield



Yes; this is one of those home maintenance routines often unknown or overlooked by most homeowners.  Although not quite as simple as flushing a toilet, you can, and should, flush your water heater regularly.  (What does that mean?)  Depends on the quality of your water supply and age / condition of your water heater.  Annually is a good place to start.

Although we don't like to think so, all domestic water has some amount of sediment in it, which finds a place to naturally settle to the bottom of your water heater.  As well, rust and scale typically is created inside your tank, and joins the sludge party.  Besides just being foul, this contributes to the inefficiency and early deterioration of the elements / anodes in an electric water heater (the "rods" which your plumber likely replaced), or inefficient operation of a gas water heater.

The operation is fairly simple, and typical for most water heaters:

-  If your water heater is gas, set the gas valve to "Pilot" to prevent the burners from coming on while you are flushing it. If your heater is electric be sure to turn off the circuit breakers.

-  Connect a garden hose to the drain valve at the bottom of the tank.  Make sure the outlet of the hose is in a safe area away from pets and children. It can be very hot and can scald quickly.

-  Close the shut off valve on the cold inlet to the water heater.

-  Carefully open the temperature/pressure relief valve at the top of the tank by lifting the lever.  Leave the valve open. Turn on the hot water side of any faucet in the house.

-  Open the drain valve at the bottom of the heater allowing the water to flow out through the garden hose.  If the sediment is clogging the drain valve then try closing the temperature/pressure relief valve and turn the cold inlet valve back on to "power flush" the sediment out.

-  In some cases the sediment hardens into large chunks that can block the drain valve.  If so, then wait until everything cools down, remove the garden hose from the drain valve, remove the valve if necessary, and use a long screw driver to break up the clog.  Mess alert!

-  If you have not performed this procedure for some time (or EVER), you might want to perform a full flush. When the tank is empty, shut off the drain valve and turn on the cold water inlet valve.  This will loosen up more sediment in the tank through the churning action of the cold water in the tank.  Let the tank fill partially and drain it again.  If you have extreme amounts of sediment, you may have to repeat this procedure a few more times.

-  When the garden hose eventually runs clear you are finished (are you a six-pack to the wind yet?).

-  Close the drain valve at the bottom of the tank and remove the garden hose.

-  Close the pressure relief valve at the top of the tank if it is still open, and turn the cold inlet valve back on.

-  Oh yes, that faucet you left open... let it run until no air bubbles come out.

-  Turn the heater back on, and with gas units re-light the pilot light if necessary.

If you're uncomfortable following this procedure, a plumber or handyman can certainly do this for you.

Whenever you disturb the water system in this way, it is not unusual to see increased amounts of sediment in your tap water.  This should clear away after running a few gallons.

Schedule this for Saturday.  You didn't have anything else to do, did you?


Hits: 25331
Comments (1)Add Comment
written by Plumbing Training, April 14, 2010
It's really nice of you outlining the hidden points of plumber nowadays. you even add up quality contents, which is an important thing to blogs like this.

Write comment
You must be logged in to a comment. Please register if you do not have an account yet.


Latest News

HomeMasons introduces Whole Home Care service

Ask Mason

If you have a design, remodeling or home improvement question, all you have to do is ask. Click here!
© 2019 HomeMasons, Inc.