There are several reasons you would want to fill a hot water heater: the hot water heater could have had a leak and the water level is low; you might have had repairs done for which you needed to drain the hot water heater; you may be flushing the hot water heater as part of regularly scheduled maintenance; or you may be installing a new hot water heater. Whatever the reason, you must follow proper procedure in order to fill the hot water heater correctly and keep it working the way it should.

Fill a Hot Water Heater

Step 1

Turn off the gas valve or shut off the electricity breaker that powers the hot water heater.

Step 2

Shut the cold water valve.

Step 3

Connect a hose to the drainage valve for the purpose of routing water outdoors or into a drain.

Step 4

Open the drainage valve (usually by turning it counter-clockwise).

Step 5

Locate a hot water faucet somewhere in the house and open it or turn it on to let air inside.

Step 6

Shut the drainage valve.

Step 7

Turn on the cold water to begin the process of filling the hot water heater.

Step 8

Wait until you notice a steady flow of water from the hot water faucet; this is an indication that the tank is full.

Step 9

Restore power.

Flush and Refill a Hot Water Heater

Step 1

Turn off the gas valve or shut off the electricity breaker that powers the hot water heater.

Step 2

Connect a hose to the drainage valve located at the bottom of the hot water heater.

Step 3

Run the hose into a drain or outside; the water from the hot water heater will drain through it.

Step 4

Close the cold water valve.

Step 5

Open the valves for pressure and temperature relief (these are located on top of the hot water heater).

Step 6

Open the drainage valve and let the water drain out. When the water begins to flow you may notice some particles--these are either sediment or scale and are normal.

Step 7

Close the drainage valve, disconnect the hose and close the pressure and temperature relief valves located on top of the hot water heater when the flow of water ceases.

Step 8

Turn on a hot water spigot in the house.

Step 9

Open the cold water valve and listen for the hot water heater to start filling.

Step 10

Turn off the faucet when a steady flow of water starts to come out of the opened hot water faucet.

Step 11

Restore power to the hot water heater.

Step 12

Allow the hot water heater to recover.

Step 13

Recheck and tighten the drainage valve.