Water Heater Leaking? What to Do

Most water heaters in Lawrenceville homes sit in a garage, an attic closet or a laundry room, and that is exactly where a slow leak can run for days before anyone sees it. A heater in an attic is the worst case, because the water goes through the ceiling below it. Here is what to do first and how to read what you find.

First: Stop the Water and the Fuel

1. Close the cold water valve on the pipe coming into the top of the heater. Turn the handle clockwise. If it is stuck or the leak continues, go to the meter box near the street and shut the main. Do not force a corroded valve.
2. Cut power or gas. For electric, switch off the breaker (usually a double breaker labeled water heater). For gas, turn the control dial to off. Do not leave a gas or electric heater running on an empty or leaking tank.
3. Keep people and pets away from the discharge pipe. Water from the relief valve can be scalding hot.
4. Drain it if the leak is steady. Run a hose from the drain valve at the bottom to a floor drain or the yard. Open a hot tap somewhere in the house so the tank can empty.
5. Mop up and photograph. Wet drywall and flooring start growing mold fast in Georgia humidity, so get fans on and take pictures for your insurance company.

Then call (770) 285-5619 and we will connect you with an independent local plumber who handles water heater repair and replacement. Tell them the age on the label, the fuel type, and where in the house the heater sits.

Where the Water Is Coming From

Top of the tank

• Supply fittings: Corroded or loose connections at the hot and cold pipes. Usually repairable. Look for green or white crust on the fitting.
• Relief valve: A single drip as the heater cycles can be normal. A steady stream means high pressure or a failing valve. Houses with a pressure-reducing valve at the main often need an expansion tank, and the heater leaks at the relief valve without one.
• Anode rod port: A weeping rod fitting is a small repair, but a rod that has been in place for a decade may not come out easily.

Bottom of the tank

• Drain valve: A cheap plastic valve left dripping is a common and fixable culprit.
• Condensation: Humid garages make a cold tank sweat. Dry the area and see if it comes back before assuming a leak.
• Burners or elements: On gas heaters, water on the burner chamber can be a leak or condensation from the flue, so have the plumber check before relighting.

Through the tank body

If water is running out of the tank itself, or the tank is rusted and wet around the seams, the inside has corroded through. There is no repair for that. Replace the heater.

Why Heaters Leak

• Age. A heater past 10 to 12 years is more likely to leak from the tank. Read the serial plate to find the age, or see how long a water heater lasts.
• A spent anode rod, which lets the steel rust from inside.
• Sediment, which overheats the bottom of the tank.
• High household water pressure or thermal expansion with nowhere to go.
• A wet location, such as a garage where a floor drain is missing and the base of the tank sits in standing water.

Repair or Replace?

Repair is reasonable when the leak is at a valve or fitting, the heater is under about 8 years old, and the repair costs well under half of a new unit. Ask the plumber for the price of each before any work starts.

Replace when the tank itself is leaking, the unit is past 10 or 12 years, or you have already had repeat repairs.

If the heater sits above living space, ask the plumber about a drain pan piped to a safe discharge point, and whether a leak sensor makes sense. If you also have no hot water, our no hot water checklist can help you sort out what failed.

FAQ: Common Questions About Water Heater Leaks