This one needs a licensed pro
Call a plumber now: the relief valve is discharging
Water or steam from the relief valve pipe can mean an unsafe temperature or pressure condition. Keep away from the end of the pipe, never block it, and call a licensed plumber right away.
Why this happens
Rheem says a discharging temperature and pressure (T&P) relief valve may mean an unsafe temperature or pressure condition, and to contact a licensed plumber immediately. Rheem says the valve is designed to open when the pressure inside the tank exceeds 150 psi or when the water gets too hot, and that without a relief valve during an unsafe condition, the pressure inside the tank would rise to the point the tank may rupture or explode. Rheem says a slow weep or dribble often comes from thermal expansion or buildup on the valve seat, and a large volume of water points to temperature, but it still says to call. This Old House's Richard Trethewey says that blocking a persistent drip can create a dangerous pressure situation inside the tank. A noisy tank and a discharging valve are different problems, so treat the discharge as the urgent one.
What to do right now
- Keep people and pets away from the end of the relief valve's discharge pipe, the pipe that runs down from the relief valve near the top or side of the tank. Rheem says the valve opens when the water gets too hot, so what comes out can be very hot.
- Never cap, plug, tie off or block the relief valve or its pipe. That is this page's own rule, and Trethewey says a persistent drip is a sign the valve needs fixing, not capping.
- Do not lift the valve's lever to test it. This Old House says testing is not always risk free and can create a leak on an older unit.
- Call a licensed plumber or an authorized water heater service provider now, before you try any shutoff, because Rheem says to contact a licensed plumber immediately when the relief valve discharges. Then, if water is flowing steadily and you are confident doing it, turn off the power at the breaker (open only the hinged panel door) or the gas at the shutoff valve, as A. O. Smith advises. Turn a gas valve by hand and never force it. Only do this if you can reach each control without going near the discharge pipe. Only touch the breaker if you are standing on a dry floor and nothing electrical is wet, because Ready.gov says not to touch electrical equipment if it is wet or if you are standing in water. If you cannot do this safely, stay back.
- Do not open the heater's panels, and do not drain or flush the tank yourself.
- Stay back from the heater until the plumber arrives. If you smell gas at any time, leave and call 911 and your gas utility from outside.
When to stop. Steam, a steady flow of water, or any water from the relief valve pipe means keep away from the pipe end and call a plumber now. If water reaches outlets or the panel, or you would have to stand in water to reach the breaker, do not touch it; stay out and call a plumber and a licensed electrician. Smoke, flames, sparks or a burning smell near the heater mean leave the house and call 911 from outside. A gas smell, or hissing near a gas line or the burner, means leave and call 911 and your gas utility from outside.
What to tell the plumber
- Water or steam came from the relief valve pipe, how much, and how often.
- Whether the heater was also popping, rumbling or hissing, and when.
- Whether there is an expansion tank on the cold line, and your house water pressure if you know it.
- The heater's make, model and age from the data plate, and when it was last serviced.
Build the full list: what to tell the plumber.
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