How to Install a Plumbing Pressure Relief Valve
- 1). Turn off the power to your water heater if it is electric, or turn the thermostat all the way down to its lowest setting if you have a gas water heater. Now refill the water heater with cool water by turning on the hot water tap in a bathtub and letting it run for 15 minutes. Turn the hot water tap off.
- 2). Turn off the cold water supply to the water heater by twisting the valve, usually located just above the tank, in a clockwise direction. Place a bucket or large pan under the outlet of the pressure relief valve overflow pipe. Pull up on the lever on top of the pressure relief valve, which is either located on the top of the water tank or mounted on the side of the tank near the top. Close the relief valve when the pressure has been released and water stops flowing from the overflow pipe.
- 3). Remove the overflow pipe from the relief valve by loosening the fitting with a pipe wrench, then unscrewing the pipe from the valve. Now remove the relief valve from the water heater by placing a pipe wrench on the valve’s fitting and turning it counterclockwise. Finish unscrewing the valve out of the tank by hand and discard it.
- 4). Prepare the threads on the new relief valve by wrapping them with a couple of layers of Teflon tape. Thread the new valve into the fitting on the water tank and tighten it with a pipe wrench in a clockwise direction. Make sure the fitting for the overflow pipe is pointed in the right direction. Screw the overflow pipe back onto the valve’s fitting and tighten with the pipe wrench.
- 5). Turn the water supply back on to the water heater. Turn on the hot water tap in a bathtub and let it run for about 5 minutes, which should expel any air bubbles from the system. Turn the tap off. Turn the power back on for electric heaters, or turn the thermostat back up for gas heaters. Check all fittings for leaks and tighten as necessary.
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