A water heater usually leaks from a loose or corroded fitting at the top, the temperature and pressure relief valve, the drain valve near the bottom, condensation on the outside of the tank, or the tank itself after rust has worn through. Where the water first appears is your best clue.
Top of the Tank
Cold water enters and hot water leaves through pipes at the top. Their fittings can loosen or corrode over time. Water that starts up there and runs down the side usually means a connection problem, not a failed tank. These leaks are often repairable.
The Relief Valve
A safety valve on the side or top of the tank lets out water if the temperature or pressure gets too high. A drip from the pipe attached to it can mean the valve is worn, the heater is set too hot, or household water pressure is high. Never plug or cap this valve.
Bottom of the Tank
The drain valve can drip if it is loose or not fully closed. A small amount of moisture on a cold day may just be condensation that dries on its own. A puddle that keeps growing under the center of the tank, with dry pipes above, usually means the tank has rusted through and needs replacement.
What to Do Now
Turn off the cold-water valve on the inlet pipe. Set a gas heater to off or pilot, or switch off an electric heater at the breaker. Keep kids and pets away from hot water on the floor. If you smell gas, get outside and call your gas utility or 911.
Once the water and power are off, a plumber can tell whether a fitting or the tank is at fault. If the heater is getting older, talking through your options with a plumber helps you plan ahead. Call JPR Plumbing at (833) 603-1840.