Water heaters
Water Heater Leaking? What to Do Right Now
Updated · By the Keystream Plumbing editorial team
Step 1: Make it safe
Close the cold water inlet valve above the tank. For electric heaters, switch off the breaker. For gas heaters, turn the control knob to Off. If water is pooling near electrical outlets, stay out of the water and shut off power at the main panel if you can do it safely.
Step 2: Find the source
Dry the area and watch where water appears.
- Top of the tank: loose inlet or outlet connections, or a leaking supply line
- T&P relief valve or its discharge pipe: excessive pressure or temperature, or a failing valve
- Drain valve near the bottom: a valve that isn't fully closed or a worn washer
- From under the tank or the tank body: internal corrosion, which cannot be repaired
Step 3: Repair or replace
Leaking fittings, drain valves and relief valves are routine repairs. A relief valve that keeps discharging may point to high water pressure or a missing expansion tank, which a plumber should check.
A tank leak means the steel lining has failed. Drain the tank to reduce damage and schedule water heater replacement.
Limit the damage
Move stored items, run a wet vac and fans, and photograph the area for insurance. A drain pan piped to a drain is inexpensive protection for the next heater, especially in attics and upstairs closets.
Frequently asked questions
Is a leaking water heater dangerous?
It can be. Water near electrical connections is a shock hazard, and a relief valve that discharges often can mean dangerous pressure. Shut off power or gas and the water supply.
Can I still use hot water if my water heater is leaking?
Not if the tank is leaking. If a fitting leaks slightly you might, but it's safer to shut it down until it's repaired.
Why is water coming out of the pressure relief valve?
The valve opens when pressure or temperature is too high, or it may be worn. Have a plumber test the pressure and check for a missing expansion tank.
Editorial note: This guide is general information for homeowners, not a substitute for an on-site assessment. Local codes and conditions vary; a licensed pro can confirm what applies to your home.
