Water Heater T&P Valve Replacement

The temperature and pressure relief valve - commonly called the T&P valve or TPR valve - is the most important safety device on your water heater. It prevents the tank from building up dangerous levels of pressure or temperature that could cause an explosion. If your T&P valve is leaking, dripping, or has never been tested, this guide shows you how to test it and replace it if needed.

What Does the T&P Valve Do?

The T&P valve automatically opens and releases water if the temperature inside the tank exceeds 210 degrees F or the pressure exceeds 150 PSI. Without a functioning T&P valve, a malfunctioning water heater could build up enough pressure to rupture the tank - a serious safety hazard.

Every water heater is required by code to have a properly functioning T&P valve. It should be tested annually and replaced every 3-5 years as a precaution, or immediately if it is leaking or fails the test.

Signs Your T&P Valve Needs Replacement

• The valve is dripping or leaking continuously
• The valve leaks after you test it and will not reseat properly
• The valve is corroded, mineral-encrusted, or has never been tested
• The valve is more than 5 years old
• The discharge pipe shows signs of repeated water release

How to Test the T&P Valve

Important: Have a bucket ready under the discharge pipe before testing.

1. Place a bucket under the T&P valve discharge pipe
2. Lift the test lever on the valve briefly - just 1-2 seconds
3. Hot water should flow out of the discharge pipe while the lever is lifted
4. Release the lever - water should stop flowing completely

If the valve does not open: It is seized and must be replaced immediately.
If the valve leaks after releasing: The valve seat is damaged and must be replaced.
If it works correctly: No action needed - test again next year.

What You Will Need

• Replacement T&P valve (correct pressure and BTU rating for your heater)
• Pipe wrench
• PTFE thread seal tape
• Garden hose and bucket

Camco Automatic T&P Relief Valve - all brass body, stainless steel spring, 3/4 inch NPT, 150 PSI / 210 degrees F rating. Fits most standard residential water heaters.

Mr. Pen 10-Inch Pipe Wrench - for removing the old valve and installing the new one.

Gasoila Yellow PTFE Thread Seal Tape - seal the new valve threads before installation.

Flexzilla Garden Hose 50ft - for draining the tank before valve replacement.

Rubbermaid 12-Quart Bucket - catch water during testing and draining.

How to Replace the T&P Valve: Step by Step

Step 1: Turn Off the Heater

Electric: Turn off the circuit breaker.
Gas: Turn the gas control knob to PILOT.

Step 2: Turn Off the Cold Water Supply

Close the cold water inlet valve at the top of the water heater.

Step 3: Drain Water Below the Valve Level

Connect a garden hose to the drain valve and drain enough water so the water level is below the T&P valve. The T&P valve is usually located on the side of the tank about one-third of the way down, or on top. Drain until water stops flowing from the drain valve.

Step 4: Remove the Discharge Pipe

The T&P valve has a discharge pipe running from it down toward the floor. This pipe is usually connected with a threaded fitting. Unscrew it and set it aside - you will reattach it to the new valve.

Step 5: Remove the Old T&P Valve

Use a pipe wrench to unscrew the old T&P valve counterclockwise. It may be tight - apply steady pressure. Once loose, unscrew by hand and remove.

Step 6: Install the New T&P Valve

1. Wrap the threads of the new valve with 3-4 layers of PTFE tape
2. Thread the new valve into the tank opening by hand
3. Tighten with a pipe wrench until snug - position the valve so the lever faces outward for easy access
4. Do not overtighten

Step 7: Reattach the Discharge Pipe

Reattach the discharge pipe to the new valve. The pipe must terminate within 6 inches of the floor or into a drain - never cap or plug the discharge pipe.

Step 8: Refill and Restore Power

1. Open the cold water supply valve
2. Open a hot water faucet to purge air until water flows steadily
3. Close the faucet
4. Restore power or gas to the heater
5. Check around the new valve for any leaks

Step 9: Test the New Valve

After the heater has heated up, test the new T&P valve by briefly lifting the lever. Water should flow and stop cleanly when released. If it leaks, the valve may not be seated correctly - tighten slightly and retest.

Important Safety Rules for T&P Valves

• Never cap, plug, or remove the discharge pipe
• The discharge pipe must point downward and terminate near the floor or into a drain
• Never install a valve with a lower pressure or temperature rating than specified for your heater
• Replace the valve every 3-5 years even if it appears to be working

Summary

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