Water Heater Leak Repair Team
The temperature-and-pressure (T&P) relief valve is the single most important safety device on your water heater, and when its discharge pipe drips, it is communicating. The message is one of three things: the valve is worn out, the system pressure is too high, or the tank is overheating. All three have fixes. None of them is 'ignore it.'
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What the T&P valve does
It opens automatically if tank temperature or pressure exceeds safe limits, dumping water to prevent a rupture. It is purely mechanical, requires no power, and is your last defense against a catastrophic tank failure. Respect it accordingly.
Cause 1: a worn-out valve
Valves fatigue. Mineral deposits from Lowcountry water crust the seat, springs weaken with heat cycles, and the valve starts weeping at normal pressure. If system pressure tests normal and temperature is correct, the valve itself is the problem — replacement runs $150–$300.
Cause 2: thermal expansion pressure
The most common cause we find in Goose Creek. When the water utility or a new PRV creates a 'closed' system, heated water has nowhere to expand, pressure spikes 20–40 psi during each heating cycle, and the valve dutifully opens. The fix is a thermal expansion tank ($300–$550 installed with valve) — not just a new valve, which would start dripping again within weeks.
Cause 3: overheating
A stuck thermostat or failed high-limit switch lets the tank overheat, and the valve opens as designed. Overheating plus a stuck valve is the genuinely dangerous combination — if your water is scalding and the valve is discharging, treat it as urgent.
What never to do
Never cap, plug, or valve-off the discharge pipe. Never ignore a valve that has started discharging after years of silence — something changed, and the valve is telling you what. Call (833) 713-2101 and we will test pressure, temperature, and the valve itself before recommending anything.
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Frequently asked questions
How do I test my T&P valve?
Lift the test lever briefly — water should flow, then stop cleanly when released. If it drips afterward, sticks, or nothing flows, the valve needs professional attention. Test annually; replace every 3–5 years in our water conditions.
My valve only drips at night — why?
Nighttime is when municipal pressure peaks (less demand on the system) and your heater runs long recovery cycles — the combination pushes marginal systems over the valve's threshold. An expansion tank usually resolves it.
Can high water pressure alone cause this?
Yes. Static pressure above 80 psi stresses the valve continuously. We check static pressure on every T&P call — a PRV adjustment or install may be part of the fix.