How to Install a Hot Water Control Valve

The safety valve on a hot water heater is known by a few names: a hot water control valve, a temperature control valve, a temperature pressure relief valve or a T&P valve. This valve is set to release water and pressure within the heater when the temperature exceeds safe limits. This valve is integral to the operation of a hot water heater within the home. If pressure builds too much within the heater, the whole apparatus could explode. Most states have made it mandatory that this valve be preinstalled on the heater.

• 1

  Turn the power to the heater off. There are two types of hot water heaters: electric and gas. If the heater is electric, turn the circuit off in the circuit breaker box of your home. If it is gas, turn the thermostat all the way down.

• 2

  Turn on the hot water in a sink or bathtub near the hot water heater. Let the water run until no hot water comes out of the faucet. This will prevent any burns during the installation process. Let the water run for about 15 minutes, and then turn off the faucet.

• 3

  Place a bucket or some other receptacle at the base of the heater near the overflow pipe. Turn off the cold water supply running into the heater. Allow the water to drain out the overflow pipe by lifting up on the lever of the hot water control valve. When the water stops draining, close the valve.

• 4

  Use the pipe wrench to unscrew the hot water control valve from the overflow pipe. Sometimes the pipes are soldered together, so you may need to use a hacksaw to free the pipes. Only cut through the soldering, and then use the pipe wrench to disconnect the valve from the pipe. Unscrew the valve from the heater itself.

• 5

  Put plumber's tape along the threads on the new hot water control valve and screw the valve into the heater and then into the overflow pipe.

• 6

  Turn the valve to let the cold water flow again. Turn on the nearest faucet again and let the water run for five minutes to make sure all of the air is out of the heater. Turn off the faucet. Turn the circuit back on or raise the thermostat, depending on the type of heater you are using. Turn on the faucet again to make sure you have hot water flowing.