Water Heaters
Why Is My Water Heater Leaking?
The short answer
First, determine where the water actually starts. Water found at the bottom of a heater may come from the tank body, drain valve, T&P discharge path, or a connection above that is running down the jacket. A confirmed tank-body leak requires replacement; a valve or connection leak may be repairable.
Common symptoms
- Water pooling under the heater
- Drip from the T&P relief valve
- Rust streaks down the side of the tank
Most likely causes
- —Corroded tank body or seam — confirmed pressure-vessel leaks are not repairable
- —Leaking or discharging T&P relief valve
- —Leaking drain valve
- —Leaking inlet/outlet connection above the tank
Safe things you can check
- ✓If you can operate the cold-water supply valve safely, shut off water to the heater. For an electric unit, use the dedicated breaker; for a gas unit, use only the manufacturer's normal shutdown controls.
- ✓Dry visible surfaces if safe and watch where water first appears; water can travel down the jacket, so the lowest wet point is not always the source.
- ✓Do not cap a T&P discharge, open electrical compartments, or disturb gas piping as a homeowner leak check.
When to call a professional
Any leak from the tank body means replacement. A leaking valve can be replaced, but act quickly — a small leak becomes a flood.
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Reviewed by Paul Hall, Owner & Licensed Plumber
The Classic Plumber · Knoxville, TN · License #4268
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