Water Heater Leaking? What to Do and Why It Happens
Short answer: If your water heater is leaking, turn off the cold water supply valve at the top of the tank, then turn off the power at the breaker (electric) or set the gas valve to "off" or "pilot." Find where the leak is coming from. A leak from the tank body usually means it needs replacing. Remove the water and dry the area within 24 to 48 hours.
A water heater holds 40 to 80 gallons or more, and it's connected to your water supply, so a failing tank keeps refilling as it leaks. If water has spread across your floor, Laurel Dry Pros provides emergency water removal in Laurel. This guide shows you how to shut it down safely and figure out what's wrong.
This is general information. Gas, electrical and water heater repairs should be done by a licensed plumber.
What to do right now when your water heater is leaking
- Shut off the cold water supply. Turn the valve on the cold inlet pipe at the top of the tank clockwise. If you can't find it or it won't turn, shut off the main water valve.
- Turn off the energy source. For electric heaters, switch off the breaker. For gas, turn the gas control knob to "off" or "pilot."
- Stay safe. Don't touch electrical parts while standing in water. If you smell gas, leave the house and call 911 and the gas company.
- Contain the water. Use towels, a wet vac or a pump to stop it spreading into finished rooms.
- Drain the tank if needed. A plumber can drain it through the drain valve to stop the leak. The water may be very hot.
- Take photos of the heater, the label and the water damage.
- Call a licensed plumber for the heater and a water damage company if water reached carpet, drywall or other rooms.
Water heater flooded the basement or utility room? Call (301) 368-0221.
Call (301) 368-0221Why is my water heater leaking?
| Where the leak is | Likely cause | Usual fix |
|---|---|---|
| Top: cold or hot water pipes | Loose fitting or corroded connector | Tighten or replace fittings |
| Top or side: T&P valve or its pipe | Too much pressure or heat, or a worn valve | Plumber checks pressure and replaces the valve |
| Bottom: drain valve | Valve loose or worn | Tighten or replace the drain valve |
| Bottom: from under the tank | Tank rusted through | Replace the water heater |
| Drips with no clear source | Condensation on a cold tank | Usually goes away once the tank heats up |
| Around the gas burner area | Tank leak or condensation | Plumber inspection |
Is a leaking water heater dangerous?
It can be. The T&P valve, short for temperature and pressure relief valve, opens to release water if the tank gets too hot or the pressure gets too high. Water from that valve may mean the tank is overheating or the pressure is too high, which a licensed plumber should check right away. Water near a gas burner or wiring is also a hazard. And a tank that rusts through can let go suddenly.
Why water heaters fail
Most tank water heaters are steel tanks lined with glass. Over time, sediment settles at the bottom and minerals and rust wear down the lining. A part called the anode rod protects the tank from corrosion, but it wears out too. Many tanks last around 8 to 12 years. The U.S. Department of Energy notes that regular maintenance helps tank water heaters last longer and work better.
What the water does to your home
A failed water heater often sits in a basement, garage or utility closet. The water spreads under walls into finished rooms, soaks carpet pad and wicks up drywall. In a closet on an upper floor, it can come through the ceiling below.
The EPA says wet materials dried within 24 to 48 hours usually won't grow mold. Fans alone can't dry carpet pad or the inside of walls. Our guide on water mitigation vs. restoration explains what professional drying involves.
How to prevent a water heater leak
- Put the water heater in a drain pan piped to a floor drain, especially on upper floors.
- Add a water leak alarm or an automatic shutoff valve.
- Have a plumber flush the tank and check the anode rod as recommended by the maker.
- Test the T&P valve once a year, or have a plumber do it.
- Check the age on the label. Plan to replace an older tank before it fails.
- Keep the area around the tank clear so leaks are easy to spot.
Does insurance cover a leaking water heater?
The water damage from a sudden tank failure is often covered by a homeowners policy. The water heater itself usually isn't, because it failed from age and wear. The Maryland Insurance Administration also notes that many policies won't pay to fix the pipe or appliance that caused the leak. See our Maryland water damage insurance guide.
Licensing in Maryland
Water heater replacement is plumbing work, and gas connections need a qualified, licensed professional. Maryland's Department of Labor notes that a home improvement contractor license doesn't authorize plumbing, electrical or HVAC work. Ask to see the plumber's license.
Local note: Water heaters in finished basements in Columbia and Burtonsville can soak carpet across the whole lower level. Upstairs utility closets in Maple Lawn and Fulton can leak into ceilings below. Older homes in Bowie often have heaters in garages or utility rooms on slabs.
If the tank soaked your carpet, our guide to drying wet carpet explains what can be saved.
Related reading: Winter brings another big leak risk, so see what to do when frozen pipes burst. If your basement took on water, read what to do when your basement floods.
When should you call a water damage professional?
Call a pro when water from the heater reached carpet, drywall, a finished room or the ceiling below, or when it sat for more than a few hours. A plumber fixes the heater. A water damage company dries everything it soaked.
Water heater leak in Laurel? Call (301) 368-0221 to reach Laurel Dry Pros for water removal and drying.
Frequently asked questions
Is a leaking water heater dangerous?
It can be. Water near a gas burner or electrical parts is a safety risk, and a tank that's failing can release a lot of hot water fast. A leaking T&P valve can also signal too much heat or pressure. Shut it down and call a licensed plumber.
Why is my water heater leaking from the bottom?
The most common causes are a rusted-through tank, a loose or leaking drain valve, or water from the T&P valve's discharge pipe running down. Condensation can also drip on new or cold tanks.
Can a leaking water heater be repaired?
A leaking drain valve, fitting or T&P valve can often be fixed. A leak from the tank itself usually means the tank has rusted through and must be replaced.
Does homeowners insurance cover a leaking water heater?
The water damage from a sudden tank failure is often covered. Replacing the water heater itself usually isn't, since it wore out with age.
How long do water heaters last?
Many tank water heaters last around 8 to 12 years. The age is often printed in the serial number on the label. Older tanks are more likely to leak.
Sources
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Read the frozen pipes burst guide →
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Read the mitigation vs. restoration guide →Water damage in Laurel?
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