Water Heater Flushing

It’s generally easy to flush a water heater; however, there is a substantial risk of injury resulting from contact with extremely hot surfaces and hot water.

Ensure to protect yourself and anyone around adequately, or consult a plumbing expert before you begin.

Also, keep in mind that the following instructions are broad and offered solely for the convenience of our customers.

No obligation is assumed by ClovisPlumbingServices.com with respect to your use of these guidelines.

If you can access the owner’s guide of your water heater, you are advised to adhere to the specific manufacturer’s instructions to your product in place of general information.

Water Heater Flushing: Step 1 & 2

For electric water heaters, switch of the breaker linked to the water heater.
For gas water heaters, set the thermostat to vacation mode setting leaving the pilot light on.
Let the heater unit cool down by waiting a few hours for the water heater unit to cool down or:
Let the heater unit cool down by using up all of the hot water in the unit.

Step 3 & 4

Shut off the cold water supply (the valve is typically situated on the cold water side).
Have a garden hose connected to the drain outlet valve situated at the base of the heater.
Leave the valve shut, with the other end placed at a suitable drain point or somewhere outside.
Ensure to keep the hose outlet lower than the water contained in the tank so as to drain completely.

Related content: Water Heater Draining

If you aren’t patient enough for the heater to cool down and decide to proceed with the hot water present, then ensure to use a hose which can tolerate hot water and that its other end is positioned at a safe location.

Also keep in mind that the hose and its outlet may be too hot for your bare hands.

The process can also be made faster by using a drain pump for your water heater.

Subject to the type of drain pump used, a water heater tank of 50 gallons can be drained between 2½ to 10 minutes rather than wait for gravity to do the work.

Step 5 & 6

Turn open any faucet near the water heater to the hot water side.
Now slowly open the drain valve of the water heater completely.
If you are making use of a drain pump, turn it on after opening the drain valve.
You can let the water drain into a clean bucket to see the amount of sediments drained.
With this you can determine the frequency of flushing required for your system.
Turn off the cold water supply.

Water Heater Flushing: Step 7 & 8

Switch off the pump as soon as the water heater is drained, and shut the drain valve.
Open the cold water supply and let it run for about 5-10 minutes.
This may help remove any extra sediment dwelling at the base of the water heater.
Shut the cold water supply and open the drain valve again (if you’re using a pump then turn it on again).
Allow this water to drain out the heater tank.
Take a look at the drained water to verify the sediment volume.
If you notice sediments in the water, then steps 7 and 8 should be repeated until it is clear of it.

Step 9 & 10

When the tank is free from sediments shut the pump off, the drain valve and then disconnect the hose.
You may wish to inspect your T&P valve and Anode rod at this point when the heater tank is emptied.
For heaters over 5 years old, we recommend a replacement of the Anode rod.
We also recommend the removal and inspection of the T&P valve for likely corrosion.
For gas water heaters, it is advisable here to check the gas vent.

Step 11 & 12

At your convenience, turn on the cold water supply to commence filling of the heater tank.
Check the drain to ensure it is closed and there are no leaks.
Leakage from the drain valve could mean that there are sediment leftovers in it.
In this case, shut the cold water supply and clean out the drain valve.
Re-open the cold water supply to fill the heater tank.
While the water heater tank is getting filled, go to the faucet in step 5 and open the hot side.
Let it run until no more air is released with the water.
Open some more faucets on the hot sides and allow them run until no more air is released alongside.
If you live in a two story building, then ensure you open a faucet upstairs too.

Water Heater Flushing: Step 13

As soon as you’re sure that no more air exists within the water heater and the flow lines, you can turn on the unit and begin using it once more.
For electric units, just turn the power switch back on. For natural gas or propane units, simply set the thermostat as desired.

Next up: Understanding Relief Valves

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