This one needs a licensed pro
Call a plumber: the relief valve is discharging
Water from the relief valve's pipe means pressure or temperature in the tank went high enough to open it. Never cap or plug it. Call a licensed plumber.
Why this happens
Rheem says the temperature and pressure relief valve opens when tank pressure exceeds 150 psi or the water reaches 210F, and to contact a licensed plumber immediately when it discharges. A. O. Smith says the valve may open because of thermal expansion in a closed system, which a properly charged expansion tank is meant to absorb. Rheem warns never to plug or cap the valve, because without it the tank may rupture or explode.
What to do right now
- Do not cap, plug or tie off the relief valve or its discharge pipe.
- Keep people away from the end of the discharge pipe; the water can be very hot.
- If water is flowing steadily, turn off the power or gas to the heater and close its cold water supply, as A. O. Smith advises.
- Note whether the house has an expansion tank on the water heater's cold line.
- Call a licensed plumber now.
What to tell the plumber
- Water came from the relief valve's discharge pipe, how much, and how often.
- Whether there is an expansion tank, a check valve or a backflow preventer on the supply.
- Your house water pressure if you know it.
- The heater's make, model and age from the data plate.
Build the full list: what to tell the plumber.
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