What should I do first if my water heater is leaking?
Stop the water, cut the energy to the heater, and keep the water from spreading. Do it in this order, and stop at any step that is not safe.
- Watch for hot water and electricity. Water from a heater can be scalding. If the water has reached outlets, cords or the electrical panel, do not stand in it to reach anything.
- Close the cold water supply valve. It is on the cold pipe running into the top of the tank. Turn a round handle clockwise until it stops, or turn a lever handle so it sits across the pipe. If you cannot reach it safely, close the main water valve for the house.
- Turn off the power or gas. For an electric heater, switch off its breaker. For a gas heater, turn the control knob to off. Only close the gas line valve if you know your system. If you smell gas, leave the house and call your gas company from outside.
- Contain the water. Pull boxes, rugs and anything stored on the floor out of the way. Towels and a wet vacuum help with a small spill.
- Take photos. Get the heater, the leak, its label and every wet area before you clean up. Your insurer and your plumber will both want to see them.
- Call for help. A plumber fixes the heater. For wet carpet, drywall or a finished basement, call a water damage company too. Who to call for water damage.
Do not try to drain a hot tank right away. Tanks stay hot for hours after the heat is off, so let it cool before anyone hooks up a hose to the drain valve.
Where is the water heater leak coming from?
Most leaks come from one of four places: the relief valve, the drain valve, the pipe connections on top, or the tank itself. Dry the floor and the outside of the tank with a towel, then watch where fresh water shows up first.
| Where the water is | What it usually means | What happens next |
|---|---|---|
| Temperature and pressure (T&P) relief valve, or the pipe running down from it | Water inside is too hot, pressure is too high, or the valve is worn | Leave the valve alone and call a plumber to check pressure, thermostat and valve |
| Drain valve near the bottom of the tank | The valve is loose, worn or was not fully closed after draining | Often a simple valve repair or replacement |
| Cold inlet or hot outlet pipes on top of the tank | A loose fitting or a corroded connector | Usually tightened or replaced by a plumber |
| Under the tank, coming from the tank itself | Often corrosion through the tank wall | Usually means a replacement |
| Near the tank but not from it | Could be a nearby supply line, an HVAC condensate drain or a washer hose | Dry the floor and watch where new water appears |
A little water at the base is not always the tank. In many Northern Virginia homes the water heater shares a utility room with the furnace, the washer and the main water line, so check those before you assume the worst.
Why is my water heater leaking from the pressure relief valve?
The temperature and pressure relief valve is a safety part. It opens on purpose when the water gets too hot or the pressure inside climbs too high, so water coming from it is a warning sign.
- High water pressure coming into the house can push the valve open.
- Thermal expansion. Heated water takes up more room. Without somewhere to go, such as an expansion tank, pressure builds until the valve lets some out.
- A thermostat set too high or failing can overheat the water.
- A worn valve or mineral buildup can keep it from sealing.
Never cap, plug or remove the relief valve. Have a plumber find out why it is opening.
Can a leaking water heater be repaired, or does it need replacing?
Valve and fitting leaks are usually repairable. A leak from the tank body almost always means a new water heater, because there is no practical way to patch a tank that has rusted through from the inside.
Age matters too. The U.S. Department of Energy lists a typical life of about 10 to 15 years for a conventional storage water heater. The label on the tank, or the serial number, usually shows when it was made, though each manufacturer codes the date a little differently. A tank near the end of that range that starts leaking is a good time to talk replacement with your plumber.
What water damage does a leaking water heater cause?
A water heater sits on the lowest floor or in a closet, so the water goes where it does the most damage: under carpet, into the bottom of drywall, and down through the floor to the room below.
- Finished basements. Carpet and pad soak up water fast, and drywall wicks it up from the bottom. Many Northern Virginia split-levels and basements put the heater right next to a family room. Flooded basement cleanup
- Upper-floor closets. In townhomes and condos the heater is often in a closet on a main or upper floor. A leak there shows up as a stain on the ceiling below. Water leaking from the ceiling: what to do
- Slow leaks. A small drip that runs for weeks can rot the subfloor and grow mold behind baseboards before anyone notices. Mold in the basement: causes and how to get rid of it
The EPA advises drying water-damaged areas and materials within 24 to 48 hours to help keep mold from growing. That is why getting the water out and the drying started matters more than how much water you see.
How do you dry out water heater water damage?
Pull out the standing water, remove what cannot be dried in place, and run drying equipment until moisture readings say the structure is dry. Here is what that looks like with us:
- We extract standing water and pull up wet carpet and pad.
- We take moisture readings in the floor and the bottom of the walls to see how far the water went.
- We cut out wet drywall and insulation that will not dry in place.
- We set dehumidifiers and air movers and come back to check the readings until they say dry. Water extraction and drying
- We photograph the damage, log the readings and write the estimate for your insurer, then meet your adjuster on site.
- The same crew rebuilds the floor, walls and trim. No handoff to a second contractor.
Wondering what that first phase is called? What is water mitigation? And for coverage questions, read Does homeowners insurance cover water damage?. Your policy and your insurer decide what is covered.
How can I keep my water heater from leaking again?
You cannot stop a tank from aging, but you can catch problems early and limit the damage.
- Set the heater in a drain pan piped to a floor drain, if your plumber says it fits your setup.
- Put a water leak sensor on the floor next to the tank.
- Look at the base of the tank and the relief valve pipe once a month for drips or rust.
- Follow the manufacturer's manual on flushing sediment.
- Ask a plumber about an expansion tank and your home's water pressure.
- Plan a replacement before the tank reaches the end of its expected life.
Already have wet floors or walls? See how our water damage restoration works, from the first call to the finished room.