Tip & How-To about Heating & Cooling

Water heaters

F your water heater suddenly seems to supply less hot water and you've made sure it isn't leaking, flush the water heater tank to be sure mineral deposits are not reducing the heater's efficiency. To do this:
1) Turn off the water heater's gas valve or electrical power.
2) Let the water cool.

3) Turn off the water inlet valve and attach a hose to the drain valve to run the water into a large bucket, or to a drain or the outdoors.

4) Open the drain valve at the base of the tank, and open one hot water faucet somewhere in the house to let in air. When all water has drained from the water heater, turn the cold water valve on and off until the water from the drain runs clear.

5) Close the drain valve, turn the water back on to fill the tank, and turn the gas valve or electricity back on (relight the pilot if applicable).

Posted by on

Heating & Cooling Logo

Related Topics:

Related Questions:

1 Answer

Why does the water suddenly runs COLD after many minutes of running hot?


Unless you are using a tankless hot water heater, there is a limited amount of hot water available in the tank. Electric and gas water tanks need time to recover after use, and if you are using heavily, it can exhaust the available supply. That said, there are a couple reasons why you may have less hot water than seems normal. In both electric and gas water heaters, silt can form in the bottom of the tank. This will build up over time and displace water. It also reduces the heating efficiency of gas units. There is a drain valve on the bottom of water heater tanks to allow for purging of this silt periodically, but few ever do it. You could also have, in the case of an electric hot water heater, a bad element or thermostat. Most electric heaters have an upper and lower element and thermostat. If one fails the other will still work, but the water takes longer to get hot and will deplete faster.

Nov 04, 2015 | Water Water Heaters

1 Answer

I have a Ariston Pro TI water heater. I am getting a lot of rust/junk/green/black, particals in the hot water plugging my shower heads. How do if fix this problem? Thanks Tom


If problem is hot water side only, then water heater is suspect.
1) If water heater temperature is set above 140F, it causes minerals to dissolve out of water.
2) If water heater is exposed to minerals in water, like hard water, those minerals will gather at bottom of tank.
3) If anode rod is depleted, the metal tank will begin to rust.
4) Combination of problems listed above.
To fix these problems, flush tank and replace anode rod, and possibly install water softener, install water filter, and turn down temperature setting.
http://waterheatertimer.org/Clean-sediment-out-of-water-heater.html#flush
http://waterheatertimer.org/Replace-anode-rod.html

Jul 11, 2011 | Bosch GL8Ti Ariston Pro Ti Electric...

1 Answer

Our hot water will last for about 5- 10 minutes then turn luke warm. I have replaced both elements but problem remains . Do you hink it is the thermostat ? thanks chazz


If you have not done so already then turn thermostats up to 140 degrees. You may also try to drain and flush tank to clean out any mineral deposits that could be hurting your effiency. To do this shut off electrical power to heater then connect garden hose to drain valve on the bottom of tank. Run hose to floor drain or other safe area and open drain valve. If it drains good with the water on then let it flush for a couple of mins. then shut incoming water supply off. Let tank drain as far as it will. You may need to open a faucet on the hot side of nearby fixture to break vacumn.
Drain it completly then close drain valve and hot side of faucet.Turn water supply back on and let tank refill. Do this 2-3 times to get inside of tank as clean as possible. Hope this helps you and thanks. P.S. You may need to replace thermostat also.

Mar 28, 2011 | Rheem 40 GAL ELEC TALL Water Heater 6YR SC...

1 Answer

My water softener emptied im not sure how long it was empty for but I dont think it was too long I filled it with salt and now it doesnt work. It still regenerates but im getting hard water still any ideas?


Do you mean the salt tank was empty? If so fill salt tank half way wait about 6 hrs for brine to develop. Manually regenerate softener 2x within 24 hrs. When the salt runs out the resin becomes saturated with hardness minerals. It takes at least 2 regeneration cycles back to back to completely restore soft water. Also the hot water will take some time to get soft. It will help to flush water heater after cold water is consistently soft.
I hope this helps,
h2oservices

Feb 26, 2011 | Culligan Compatible S7011C RS23SED5...

1 Answer

my water heater won't circulate water. i think it is clogged with calcium


One thing you might try is to shut off power or turn gas valve to pilot,as you didn't say if it was gas or electric. Hook up garden hose to drain valve and run hose to floor drain or sump basin. Shut off water supply valve to heater. Open drain valve and if you get a decent flow then let it drain tank about half way. If flow rate drops drastically then open hot side on faucet nearby to break vacumn.When you think tank is about halfway drained then shut off faucet if you opened one and close drain valve. Turn water supply valve back on and let tank refill. When it is full leave supply valve on and open drain valve and let water flush thru system for several mins. Close drain valve and run water on both hot and cold side of faucets fartherest away from heater as possible. Close this faucet
Turn tharmostat up as high as it will go and let heater run till it shuts off then return thermostat to original setting. Go through the drain and flush procedure a couple more times and this shold help break mineral deposits loose and flush them out. This should make for more efficeint operation and help prolong the tank life. Hope this helps you. Have a good new year and thank you.

Jan 02, 2011 | Whirlpool Heating & Cooling

Not finding what you are looking for?

977 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Heating & Cooling Experts

Paul Carew

Level 3 Expert

2557 Answers

Dan Webster
Dan Webster

Level 3 Expert

8220 Answers

Donni Steen

Level 3 Expert

659 Answers

Are you a Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Loading...