The T&P valve (temperature and pressure) is the most critical part of your hot water tank and it needs to operate correctly at all times. The maximum temperature rating of the valve is 210 degrees and 150 psi. If you valve is defected you can risk the danger of your water tank exploding. The T&P valve is brass and is located either on the top or side of the water heater. There is also a lever on the valve that is used to test it. It also has an overflow pipe attached that’s a few inches above the floor. The valve should be tested every couple of years.
Tools and Material:
New T&P valve
Garden Hose (Step4)
Test the valve by placing a small bucket under the overflow pipe. Lift up the lever on the valve to let out some water. If water keeps coming out of the valve after the lever is back in position, the valve will need to be replaced. The same holds true if the pressure valve is found leaking water before the test.
If you have a gas hot water heater, turn the temperature all the way down. If you have an electric hot water heater, turn of the circuit breaker supplying the power.
Turn on the hot water to the bathtub and let it run until it is no longer hot; warm is ok.
Turn off the cold water supply to the hot water tank and raise the lever on the T&P valve until the water stops flowing. If the water does not stop after several minutes, you may need to drain some of the water from the drain valve at the bottom of the tank by using a garden hose.
Using a pipe wrench, unscrew the overflow pipe from the valve and then unscrew the valve from the tank.
Apply Teflon tape to the new T&P valve and screw it into the tank using a pipe wrench. Reattach the overflow pipe to the new valve.
Turn the cold water supply back on and open the hot water valve on the bathtub for a minute or two to make sure all the air is out of the system.
Turn the electric back on to your hot water heater or if its gas, turn the water temperature setting back to where you had it; check for leaks. The job is now complete.