Water heater leaking

Find the source before pricing the problem. Water at the top usually comes from the inlet or outlet fittings, the heat-trap nipples or an overflowing relief-valve discharge; water at the bottom can be the drain valve, condensation on cold pipes, the tank body itself, or water running down from a top leak. A tank body leak is a pin-hole or seam failure in the steel: it cannot be patched or sealed and the unit must be replaced. Everything else is a part, and parts are replaceable.

Relief-valve discharge has its own causes: a valve lifting because of overpressure (often thermal expansion on a closed system with a backflow preventer, which is what the expansion tank solves), a valve that has failed open, or sediment holding it off its seat. A valve that discharges only during heating, then reseats, points to expansion; one that runs continuously even cold points to a failed valve or supply pressure.

Close the cold-water shut-off above the heater to stop the flow, and turn the gas control to OFF or switch off the electric breaker if you can do so safely. Keep clear of water near electrical parts, and do not cap or plug the relief-valve discharge pipe under any circumstances: it is the tank's pressure relief, and plugging it turns the tank into a pressure vessel.

Mop and dry the area so the source can be seen, and note whether the drip changes when the heater fires or when water is drawn. That observation tells the technician whether to bring a valve, a fitting kit or a replacement quote.

A confirmed tank-body leak ends in replacement: the tank lining has failed and no repair restores it. CANRO states standard 40 or 50 gallon tanks are typically replaced same-day or next-day, and replacement estimates are free, so the leaking call becomes a quoted replacement rather than a repair. A leak from a fitting or valve is a repair, priced after the diagnostic visit confirms the source.

Water damage restoration is separate from the heater work: the plumber stops the leak and replaces the heater, and any flooring or drywall repair is quoted by the trades that do it.