# Water heater leaking: what to do now Updated: 2026-10-24 ยท https://pros411.com/en/guides/plumbers/water-heater-leaking ## Short answer If your water heater is leaking and you smell gas, leave the house and call 911 or the gas company from outside. No gas smell? Turn the heater off: gas knob to OFF or PILOT, or switch off its breaker if it is electric. Then close the cold water valve on the pipe at the top of the tank and put towels around the base. If the tank itself leaks, it needs replacing. > Safety first: Gas smell? Get everyone out of the house. Do not flip light switches or use your phone inside. Call 911 or your gas company from outside. The water in the tank can be hot enough to burn you: do not open the drain valve or the relief valve. ## What to do when your water heater leaks ![Cartoon water heater leaking a puddle at its base while a cat watches](https://pros411.com/img/guias/water-heater-leaking.webp) 1. **Water at the base? Check for gas first.** A puddle around the heater means act now. If you smell gas, do not touch anything: get everyone out and call 911 from outside. 2. **Turn off the gas or the power.** Gas heater: turn the knob on the gas control, near the bottom, to OFF or PILOT. Electric heater: switch off its breaker (it may say WH), standing on a dry floor. 3. **Close the cold water valve on top.** It is on the cold pipe that goes into the top of the tank. Turn it clockwise until it stops: no more water goes in. 4. **Catch the water and find the leak.** Put towels and a bucket at the base and move boxes away. Dry the tank and watch: a drip from the pipes on top is often a loose connection. 5. **Leaking from the tank itself? Replace it.** Water from the tank body or rust at the bottom means the tank is rusting from the inside. That cannot be fixed: a plumber replaces the heater. ## Where the water comes from - From the pipe on the side that runs down toward the floor: the relief valve is letting water out. It is a safety valve. Never cap or plug it; call a plumber. - From the pipes on top, where water goes in and out: often a loose or rusted connection. That is usually a repair, not a new heater. - From the drain valve, the little spigot near the bottom: it may not be fully closed, or its washer is worn. - From under the tank with no clear source, or rusty water around the base: the tank is likely rusting from the inside. The heater needs replacing. - Condensation: on a new tank or a very cold day, the outside can "sweat". It stops on its own and leaves only a little water. ## Repair or replace? Tank water heaters commonly last around 8 to 12 years. If yours is that old and has rust or a leaking tank, ask the plumber for a replacement quote. Ask if the price includes hauling away the old one and the permit. Also ask about anything local code requires, like an expansion tank, a drain pan or new venting. ## When to call a plumber - Any gas smell (call 911 or the gas company first, from outside). - Water coming from the tank itself or rust around the base. - The relief valve keeps releasing water or steam. - You have no hot water and the area is wet. - Water is spreading in a closet, attic or garage, where it can damage floors and ceilings. Find plumbers in your city: https://pros411.com/en/plumbers ## Frequently asked questions ### Is a leaking water heater an emergency? It is urgent if you smell gas, the relief valve keeps letting out water, or water is reaching walls, floors or outlets. Turn off the heater and the cold water, then call. Use the "24/7 emergencies" filter to find plumbers who answer now. ### Can I still use a leaking water heater? No. With the heater off and the cold water closed, the leak slows down and the heater cannot overheat. Turn it back on only after a plumber checks it. ### Why is my water heater leaking from the bottom? Most often because the tank is rusting from the inside, and that cannot be fixed. Less often it is the drain valve, or water running down from a connection on top. Dry the tank with a towel and watch where the water shows up first. ### Why is my water heater leaking from the top? Usually a loose or rusted connection on the hot or cold pipe, or the relief valve. That is often a repair, not a new heater. Turn off the heater and the cold water, then call a plumber. ### Why is water coming out of the relief valve pipe? Because the water is too hot, the pressure is too high or the valve is worn out. The relief valve is a safety device: never cap or plug it. Turn off the heater and call a plumber. ### Do I need a permit to replace a water heater? In many cities, yes. Ask the plumber if the permit is included in the quote.