A puddle under the water heater is one of those things that’s easy to ignore until it becomes a flooded utility closet. The good news: not every leak means a new tank. The bad news: some of them do, and waiting rarely makes it cheaper. Here are the six causes we run into most in Fort Mill and Tega Cay homes.
1. A loose or failing drain valve
At the bottom of the tank is a drain valve used for flushing sediment. Over time it can loosen or fail to seal, letting a slow drip escape. Sometimes it’s as simple as snugging it up; if the valve itself is worn, it needs replacing. This is one of the cheaper fixes.
2. The temperature & pressure (T&P) relief valve
The T&P valve is a safety device that opens if pressure or temperature climbs too high. If you see water near the discharge tube, the valve may be doing its job (a sign of a real pressure problem) or it may simply be worn out. Either way, don’t cap or ignore it — that valve is what keeps the tank from becoming dangerous.
3. Sediment buildup
Our area has its share of hard water, and minerals settle to the bottom of the tank over the years. That layer makes the burner work harder, overheats the steel, and accelerates corrosion until the tank springs a leak. Annual flushing slows this down a lot.
4. Loose inlet or outlet connections
The cold-in and hot-out fittings on top of the heater can loosen with years of expansion and contraction. A leak up top is often just a connection that needs to be tightened or re-sealed — usually a quick repair.
5. A cracked or corroded tank
If water is coming from the body of the tank itself, the inner lining has likely corroded through. There’s no patch for this — the unit needs to be replaced. Most tank heaters last 8–12 years, so if yours is in that range and leaking from the shell, replacement is the honest answer.
6. Too much pressure
High household water pressure (above ~80 psi) stresses every fixture in the house, the water heater included. If a tank keeps having problems, it’s worth checking whether a pressure regulator is needed.
What to do right now
If the leak is active, shut off the water supply to the heater and, for an electric unit, cut power at the breaker (for gas, set it to “pilot”). Then call us. We’ll tell you honestly whether it’s a repair or a replacement — see our water heater repair & installation page for what that involves, or read about emergency & leak repair if water is actively spreading.
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