Water Heater Leaking From the Bottom?
Causes & What to Do Next

Finding a puddle under your water heater is worrying, but not every leak means you need a new heater. Some leaks come from a valve or fitting that is a quick repair. Others mean the tank itself has rusted through. Here's how to stay safe, find the source and decide what to do next.

First: Make It Safe

1. Turn off the energy source. For an electric heater, switch off its breaker. For a gas heater, turn the gas control knob to OFF or PILOT.
2. Shut off the cold water supply using the valve on the cold inlet pipe at the top of the heater.
3. Protect the area. Move stored items away and mop up so you can see where new water appears.

Is It Really the Water Heater?

Before assuming the worst, dry everything and lay paper towels around the base. Then check nearby sources: supply lines and fittings on top of the heater, a furnace or AC condensate line, a water softener, or condensation on cold pipes. Gas water heaters can also produce a small amount of condensation when they fire up with very cold incoming water. That's normal and usually stops once the tank warms up.

The 5 Most Common Sources

1. Drain valve. The valve near the bottom of the tank can drip if it's loose, worn or full of sediment. Gently tightening it or fitting a hose cap may stop it; otherwise the valve can be replaced without replacing the heater.
2. Temperature & pressure (T&P) relief valve. If water is coming from the discharge pipe that runs down the side of the tank, the valve is opening because of excess pressure or temperature, or the valve itself is failing. Never cap or plug this pipe. High household water pressure or a missing expansion tank are common causes and need a plumber.
3. Inlet and outlet connections. A slow drip from the fittings on top can run down the jacket and pool at the bottom, so it looks like a bottom leak.
4. Gas burner area. A little condensation is normal. Steady dripping into the burner compartment is not, and it can put out the pilot or rust the burner.
5. The tank itself. If water is seeping from under the jacket or the bottom seam, the inner tank has corroded through. A leaking tank can't be repaired and needs to be replaced.

Repair or Replace?

Leaks from the drain valve, T&P valve or fittings are usually repairable, often in an hour or two. A leak from the tank body means replacement. We'll show you where the water is coming from and give you a firm price for either option before any work starts. See our water heater repair and replacement service for details, including same-day installs.

How to Prevent Leaks

• Flush the tank once a year to clear sediment (maintenance checklist)
• Have the anode rod checked every few years so it can keep protecting the tank
• Install a thermal expansion tank if you have a check valve or pressure regulator on your main line
• Put the heater in a drain pan piped to a floor drain, especially if it's in a closet or upstairs

Frequently Asked Questions