Turn the valve on the cold pipe at the top of the heater clockwise until it stops. This keeps more water from filling a tank that's already failing.
For electric units, flip the breaker. For gas, turn the dial on top to 'off.' A dry element or burner running against a leaking tank makes things worse fast.
Feel along the connections up top and the drain valve near the floor. If those are dry but the pan is filling, the tank itself is leaking and it won't be fixable.
Shift boxes, laundry, or stored items away. A slow drip can become a full tank of water on the floor without much warning.
Most bottom leaks come down to age. Tanks rust from the inside out, and once the steel gives way, no patch or seal will hold it. If your heater is more than about ten years old and water is coming from underneath, replacement is almost always the honest answer.
Before assuming the worst, a plumber checks the easy stuff first: the drain valve at the base, the cold and hot connections up top, and the temperature relief valve on the side. Any of those can drip and trickle down to the floor, which looks exactly like a tank leak but is a simple fix. That's why we look before we quote anything.
Homes around Marina and Seaside often run on hard water pulled through the local supply, and mineral buildup speeds up corrosion inside the tank. Garages here also sit on sandy ground, so a slow leak can soak into the slab or drywall before you notice a puddle. If the base is actively pooling, treat it as urgent and get the water shut off.
When you call, tell us the age of the unit and whether it's gas or electric. Our plumber can usually be at your door in about 45 minutes across Marina, Sand City, and Monterey to confirm the source and get you hot water back.
Describe what you're seeing to a real Marina plumber: call (210) 555-0134 or send the form. Free, no obligation.