How to Flush Your Water Heater


Manufacturers recommend flushing the sediment from your heater periodically.  By following these recommendations you will not only extend the life of your water heater but also save on the cost of using it.

Refer to the owner's manual for the recommended schedule, as each unit will vary and depend upon the quality of water in your area.  Areas with high mineral content will have to be flushed more often, than a unit that is properly connected to a filtration system.

What is sediment?  Sediment is the sand, minerals, and other grit from your well or the municipal water company.  It is a normal part of a water system in most areas but can also be deposited into your water lines after the city or county has flushed their lines.  Over time this sediment builds up in the bottom of your water heater.  This build up causes corrosion of the tank and reduces the efficiency of your water heater costing you more money.

By cleaning your water heater regularly and flushing this sediment out, you will extend the life of your heater and will lower the energy required to run your existing unit, possibly saving yourself hundreds of dollars.  Please read all steps before starting this procedure.


Step 1 - 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.  With an electric water heater, if the water level drops below the heating elements, the thermostat will turn the elements on - this will cause the elements to fail and they will have to be replaced.

Step 2 - Connect a garden hose to the drain valve at the bottom of the tank and drag the other end of the hose out side and away from your home. .

CAUTION: Keep draining water away from pets and children. It can be very hot and can scald quickly. (Do not open drain yet.)

Step 3 - Close the shut off valve on the cold inlet to the water heater.

If you do not have a shut off valve located at your heater or if it does not work, you will have to shut your water off at the main water line coming into your home or at the meter.

Step 4 - Carefully open the temperature/pressure relief valve at the top of the tank by lifting the lever.  (Usually the gold thing w/ the silver thingy on it coming out the side or top of your heater) Leave it open.

Step 5 - 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.  This is a very wet and messy procedure.  Have a shop vac handy!

Step 6 - When the garden hose runs clear you are finished.

Step 7 - Close the drain valve at the bottom of the tank and remove the garden hose.

Step 8 - Close the pressure relief valve at the top of the tank if it is still open, and turn the cold inlet valve back on.

Step 9 - Open a hot water faucet in your house, and let it run until no air bubbles come out.

It may spit and sputter, we have actually had customer's think it was going to explode - nothing to worry about, it is just air in the lines.

Step 10 - Turn the heater back on, and with gas units re-light the pilot light if necessary.

Tips & Warnings

  • When you flush your heater:  If the water is brown or rust in color this could be an early warning signal.  This indicates that your water heater has started to deteriorate internally and will eventually begin to leak.  Replacing your water heater sooner rather than later will save you time, money, and stress!
  • You may experience some discoloration in the water for a few hours after flushing. This is only sediment in the lines that has been dislodged and has traveled thru to your fixtures.  This is normal and should clear up after a few uses.
  • CAUTION: When flushing your water heater there is danger of being scalded. Be careful and keep children and pets away during the procedure.
  • You must TURN OFF the CIRCUIT BREAKERS to electric water heaters before starting this procedure to avoid frying the elements.
Call or set up an appointment online for the plumbing experts at Michaels Plumbing Service if you are unable to or are uncomfortable with flushing out the water heater.   Michaels Plumbing Service (770) 592-0081 or online for service.

Published with permission - this article was originally published on October 9, 2009 under the byline Katrina Derrico at eHow.com - http://www.ehow.com/how_5512142_flush-water-heater.html

Not what you are looking for? 

All Services  |  Water Heater Main Page  |  Hot Water Heater Articles, Rebates and How To's  |  How to flush your water heater  |  How to install a water heater blanket  |  Why do water heaters fail?  |  How does a tankless water heater work?  

Other Services We Offer:

All Services |   Bathroom Plumbing  |  Gas Systems  |  Home  |  Kitchen Plumbing  |  Retail Installations  |  Schedule Appointment Online  |  Sewer and Drain  |  Water Heaters  |  Water Line Replacement and Repair  |  Home Care Club  |  Contact us

Request Appointment Today
* Notes Required Fields
Image Verification
To help us cut down on spam, please copy the letters you see into the space provided, then click Submit.