Being able to locate the pressure relief valve on your water heater is important. It’s the part of the machine which prevents the Temperature and Pressure from climbing to dangerous levels, which is why it’s sometimes called the T&P valve. Occasionally testing the valve or at least knowing what to look out for in case it’s the cause of any issues could save you a lot of pain and worry.
What Does the Valve Look Like?
The squat ‘T’ shape of these metallic valves reminds some people of the head of a garden hose. One end is attached to the water heater. The end opposite to that has a knob or lever which could be used to manually open the valve. A pipe comes out of the third end.
Where Can I Find It?
No matter what kind of water heater you have, the pressure valve will be located either on the top or side of the unit. Most likely, it will be near the electric supply or hot water output tube.
Don’t confuse it with the drain valve, which is used to empty the water out of the heater. The T&P valve should be the only faucet with a long tube coming out of it and pointing down. That is the discharge pipe.
How Does It Work?
Most T&P valves are calibrated to automatically open if the heater’s internal pressure exceeds 150 psi or if the temperature exceeds 210℉. This prevents the unit from exploding. When the valve opens, hot air and water go down the discharge tube. If you notice the valve leaking or warm water pooling around your heater, consider calling a plumber. Most plumbers recommend replacing the valves at least every two years.
You could also opt to test it on your own before calling a plumber. Take care to wear protective clothing like closed-toed shoes and gloves. Placing a bucket under the discharge pipe, you could manually open the valve by using its knob/lever. Wait for about three seconds and abruptly let go of the handle. If it fails to shut itself off completely, it is likely broken.
With these guidelines you shouldn’t have to hunt out your water heater’s user manual for the pressure relief valve. Replacing a relief valve can be a tricky procedure best left to the professionals. If you live in the Triangle area and want help from professionals with four generations of experience call Acme Plumbing at (919) 688-1348.