Water Heater Leaking From Bottom

A water heater leaking from the bottom usually means the inner tank has rusted through and needs replacing, though it can also be a loose drain valve or a leaking temperature relief line. Once the tank itself corrodes, it can't be patched. Shut off the water and power, then have a plumber confirm the source.

Do this right now

Turn off the water supply

Find the cold water valve on top of the heater and turn it clockwise until it stops. This stops fresh water from feeding the leak.

Cut the power or gas

For an electric unit, flip the breaker. For gas, turn the dial to 'off' or 'pilot'. Running a heater with a leaking tank can damage the element or burner.

Mop up and place a towel or pan

Soak up standing water so you can see if the puddle keeps coming back. That tells the plumber whether it's a slow weep or a real breach.

Snap a photo of the label

Get a picture of the model and serial sticker. It helps us match a replacement fast if the tank is done.

Most water in a Hollister garage or utility closet under the tank comes from one of three spots. The drain valve at the base can drip if it wasn't closed all the way. The temperature and pressure relief valve can discharge down its tube. Or the steel tank inside has corroded and split, which is the one you can't fix.

Our hard groundwater is tough on water heaters here. Minerals settle at the bottom of the tank and bake against the burner, which speeds up rust from the inside. That's why a lot of tanks in this valley start failing sooner than the sticker suggests. A plumber checks the valve fittings, the relief line, and the base of the tank, then flushes or tests to see exactly where the water starts.

Treat it as urgent if the puddle grows back after you dry it, if you smell gas, or if the water is rusty. A tank that's actively leaking can fail all at once and dump dozens of gallons across the floor. If it's just a slow drip from a fitting, you have a little more time, but don't ignore it.

Common questions

Can a leaking water heater be repaired instead of replaced?

If the leak is at the drain valve, a fitting, or the relief valve, yes, those parts can be swapped. If the leak is coming from the tank body itself, the tank is rusted through and has to be replaced. A plumber can tell the difference in a few minutes.

Is it safe to keep using hot water until you arrive?

No. Shut off the cold supply and the power or gas. Using it while it leaks can burn out the element or heat an empty tank, which makes things worse and less safe.

How long does replacing a water heater take?

A standard tank swap usually takes a couple of hours once we're on site with the right unit. We can often bring a matching size the same day after we see your setup.

Still not sure?

Describe what you're seeing to a real Hollister plumber: call (831) 555-0142 or send the form. Free, no obligation.

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