Rheem Water Heater T&P Relief Valve Replacement — What This Part Does
The Temperature and Pressure Relief Valve (T&P or TPR) is a mechanical safety device that protects your Rheem water heater tank from dangerous over-temperature or over-pressure conditions. The valve opens automatically to discharge water if internal temperature exceeds 210°F or pressure climbs above the rated limit, typically 150 psi on Rheem tanks. The valve has a bronze body with a 3/4-inch MNPT threaded inlet that screws into the tank and a 3/4-inch FNPT outlet for the discharge pipe.
T&P valves fail when the internal seat wears out, mineral scale builds up and prevents proper sealing, or the valve body itself becomes damaged or corroded. Once the valve starts weeping or dripping it won’t reseal reliably, and the only fix is full replacement with a new valve that matches your tank’s BTU rating, pressure rating, and temperature probe length. Installing the wrong valve or skipping the replacement leaves your water heater without proper overpressure protection.
Signs It Needs Replacing
- Water dripping or running from the T&P discharge tube You see a steady drip or stream of water coming out of the relief valve drain pipe, even when no hot water is running.
- Wet or corroded valve body The valve itself is damp, has mineral buildup around the threads, or shows rust and corrosion at the connection point.
- Relief valve lever won’t spring back after test You lift the test lever and it stays open or continues to leak water instead of snapping shut cleanly.
- Valve lifts and discharges repeatedly during normal operation The valve opens on its own during heating cycles or when you draw hot water, signaling either a worn valve or excess system pressure.
- Visible scale or mineral deposits blocking the valve seat Hard water scale has formed around the valve opening or on the temperature probe, preventing the valve from seating tightly.
- Puddles near the water heater with no other visible leak source Water collects on the floor near the heater and traces back to the T&P valve or its discharge piping, not the drain valve or fittings.
How to Replace It
- Turn off electrical power at the breaker (electric models) or turn the gas control to OFF (gas models), then close the cold-water inlet shutoff valve above or near the water heater.
- Open a hot water faucet anywhere in the house to relieve pressure, then attach a garden hose to the tank drain valve and run it to a floor drain or outside.
- Drain the tank down below the level of the T&P valve by opening the drain valve (for side-mounted valves drain about one-quarter of the tank, for top-mounted valves you may only need a few gallons).
- Disconnect the discharge pipe from the old T&P valve outlet, then use a pipe wrench to unscrew the valve body counterclockwise from the tank fitting.
- Wrap the threads of the new valve inlet with two to three turns of Teflon tape (if allowed by local code), then thread the new valve into the tank opening by hand to avoid cross-threading.
- Tighten the new valve snugly with a wrench, being careful not to overtighten and crack the valve body or damage the tank threads.
- Reconnect the discharge piping to the valve outlet, making sure the pipe runs downward to a safe drain location and is supported along its length.
- Close the drain valve, reopen the cold-water inlet, and let the tank refill while keeping a hot faucet open to purge air until water flows steadily.
- Restore power or turn the gas back on, then test the new valve by lifting the lever briefly to confirm water discharges and the valve reseats cleanly without leaking.
The Part You Need
| Part | Notes |
|---|---|
| Rheem T&P Relief Valve (210°F / 150 psi, 3/4-inch MNPT) | Amazon | Match the temperature rating, pressure rating (75 to 150 psi), probe length, and BTU capacity to your tank. Find your water heater model and serial number on the label affixed to the side of the tank, then cross-reference with Rheem parts lookup or supply house to get the correct valve specification for your heater’s BTU input and installation location (top or side mount). |
Related Error Codes
If this part is failing you may also see one of these codes:
When to Call a Pro
Call a licensed plumber or water heater technician if you find the valve lifting repeatedly even after replacement, which points to over-pressure from thermal expansion, a faulty expansion tank, or excessive incoming water pressure that requires backflow preventer or pressure-reducing valve work. Also call a pro if your local code requires a licensed plumber for any water heater pressure-relief work, if the valve threads in the tank are damaged or corroded, or if you’re not comfortable draining the tank and working with threaded pipe fittings. For gas water heaters, any work beyond the T&P valve replacement (burner, gas valve, or venting issues) should be handled by a qualified gas technician. For gas line, burner, or igniter work, or if you ever smell gas, stop and call a licensed technician.