If your water heater pressure relief (T&P) valve is leaking, dripping, or not working, it may be caused by high pressure, overheating, or a worn valve. This is a critical safety device—fix it promptly.
Quick Answer
Common Problems
Why It Leaks
How to Test the Valve
How to Replace the Valve
FAQs
The temperature and pressure relief (T&P) valve protects your water heater from dangerous pressure buildup. If it fails, the results can be severe—so it’s important to keep it working properly.
Quick Answer
If your T&P valve leaks, first check water pressure and temperature. If conditions are normal, replace the valve. If it doesn’t release water when tested, replace it immediately.
Common T&P Valve Problems & Fixes
| Problem | Likely Cause | What to Do |
|---|---|---|
| Dripping water | Thermal expansion or minor debris | Test valve or monitor |
| Constant leaking | High pressure or worn valve | Check pressure, replace valve |
| No discharge when tested | Stuck or failed valve | Replace immediately |
| Sudden discharge | Overheating or overpressure | Shut down system and inspect |
Why a Water Heater Relief Valve Leaks
A small amount of dripping may be normal, but frequent or continuous leaking signals a problem:
- High water pressure (typically above 80 psi)
- Water overheating (above ~120–140°F)
- Thermal expansion during heating cycles
- Worn or faulty valve
Important: If hot water is discharging forcefully, turn off the heater and power immediately.
A failed safety valve can allow dangerous pressure buildup.
How to Test a Water Heater T&P Valve
Test the valve periodically to ensure it works properly:
- Place a bucket under the discharge pipe
- Lift the valve’s lever briefly
- Hot water should flow out
- Release the lever—it should snap closed
Note: If the valve leaks after testing, it likely needs replacement.
A leaking or corroded valve should be replaced.
How to Replace a Water Heater T&P Relief Valve
Follow these steps carefully:
- Turn off power and water supply
- Drain water below valve level (1–10 gallons depending on location)
- Lift the valve lever to release pressure
- Remove discharge pipe
- Unscrew the old valve (counterclockwise)
- Wrap threads with pipe tape
- Install new valve and tighten
- Reconnect discharge pipe
- Refill tank and test
Drain water below the valve before removing it.
Caution: Water in the tank may be very hot—use gloves and take care.
To Hire a Plumber…
If the repair turns out to be more complicated than expected, you can always find a qualified plumber near you.
For hiring advice, see Trade Secrets for Hiring the Right Plumber.
FAQs
Is a leaking T&P valve dangerous?
Yes. It may indicate excessive pressure or a failing safety device.
Should a relief valve drip?
Occasional dripping can occur, but continuous leaking is not normal.
Can I replace the valve myself?
Yes, if you follow proper safety precautions.
What happens if the valve fails?
Pressure can build to dangerous levels inside the tank.
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