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Why Is My Water Heater Leaking Water?
Most water heaters leak because of a corroding tank or loose pipe connections, but pooling water can have plenty of other causes. Learn what to do immediately after spotting a leak and the possible causes.
Home Comfort Experts provides expert solutions and helpful insights for concerned homeowners.
Do This First: Stop the Water and Power
Water damage can cost homeowners thousands of dollars in repairs. The first step is to mitigate damage by shutting off the power and water supply. Homeowners should:
- Shut Off the Water: Close the water supply valve leading to the water heater.
- Turn Off the Power: For an electric water heater, switch off the breaker. For a gas unit, turn the control to pilot or off, depending on the manufacturer's instructions.
- Document the Damage: If damage is substantial, take photos or videos for your insurance claim.
- Remove Standing Water: Use a mop to remove water as quickly and safely as possible. If the water keeps leaking, use towels and buckets to prevent it from spreading.
- Dry the Area: Even slightly damp flooring or walls can mold. Dry the area completely to prevent further damage.
If water continues to leak from your traditional tank water heater, then it’s time to drain the tank. Follow the manufacturer's instructions or call your local plumber for assistance.
Leaking Water Heater Causes
Understanding why your water heater is leaking starts with identifying where the water is coming from. Keep in mind that water can travel down the outside of the tank, so a puddle at the bottom doesn't always mean the leak started there.
Water Heater Leaking From the Top
A leaky water heater is cause for concern. Here are possible causes when the leak comes from the top of the heater.
- Loose or Damaged Water Connections: The hot-water outlet and cold-water inlet connections can loosen or deteriorate over time. If you see water around the pipes or fittings at the top of the unit, you may need to tighten or replace a connection.
- Faulty Temperature and Pressure (T&P) Relief Valve: Depending on the hot water heater design, the T&P valve may be located near the top or upper side of the tank. A damaged valve can drip or leak even when tank pressure is normal.
Water Heater Leaking From the Bottom
The drain valve is located near the bottom of a water heater tank and is used for flushing and draining. A loose valve may simply need tightening, while a cracked or worn valve may need replacement.
Leaks That May Appear at Either Location
These leaks can pop up anywhere.
- High Water Pressure: Excessive plumbing pressure puts additional stress on the tank, valves, fittings, and connections. Depending on the affected component, the leak may show up near the top, side, or bottom of the water heater.
- Internal Tank Damage: Failing to replace the anode rod and/or long-term wear can weaken the tank and eventually cause cracks or leaks. Because water can run down the tank before reaching the floor, the visible puddle may not reveal where the leak actually started.
As a water heater ages, the tank itself can deteriorate. Tank-style water heaters commonly last about 10 to 12 years, and tankless water heaters can last up to 20 years, though lifespan varies with maintenance, water quality, installation, and usage.
If a tankless unit develops a leak or another performance issue, a technician can determine whether replacement or tankless water heater repair is needed.
When a Leak Means Replacement
Not every water heater leak means you need a new unit. Loose connections, a faulty drain valve, or a faulty T&P valve can often be repaired. The bigger concern is water leaking from the tank body itself.
If the tank has rusted or corroded enough to leak, patching it isn't a reliable repair. The tank is under constant pressure, and corrosion typically means the metal has weakened. In this case, water heater replacement is generally the safest long-term solution.
Use this chart to help decide between water heater repair or replacement, or call the professionals at Home Comfort Experts for assistance.
| Leak Location | Likely Cause | Repair or Replace? |
|---|---|---|
| Top of the water heater | Loose or damaged hot-water outlet or cold-water inlet connections | Repair: Connections can often be tightened, resealed, or replaced. |
| Top or upper side | Faulty temperature and pressure relief valve | Usually repair: A faulty valve can typically be replaced. High pressure or temperature should also be ruled out. |
| Bottom near the drain valve | Loose, cracked, or worn drain valve | Usually repair: Tightening or replacing the drain valve may stop the leak. |
| Top, side, or bottom | Excessive water pressure stressing valves, fittings, or the tank | Depends: Correcting the pressure and repairing the affected component may solve the problem. Tank damage may require replacement. |
| Tank body or unexplained pooling underneath | Internal corrosion, cracks, or other tank damage | Replace: A leaking tank generally can't be reliably repaired and typically means the water heater needs replacement. |
| Multiple areas on an older unit | Age-related deterioration of seals, valves, connections, or the tank | Depends: Replace individual components if the tank is sound. If the tank itself is corroded or leaking, replacement is usually the better option. |
Call Home Comfort Experts at (574) 221-8595 or schedule online today.
Schedule OnlineFrequently Asked Questions
Stop using a leaking water heater until you know where the water is coming from. A leaking tank can cause significant water damage. Shut off the water and energy supply if you can't identify the source or the leak is actively spreading.
If the tank itself is leaking, it must be replaced. Its remaining life is zero. If the leak isn't from the tank itself, a professional can fix or replace the damaged part.
Yes, it can be. It can lead to mold growth from standing water, electrical issues, possible fire, and gas leaks if you have a gas water heater.
Technically, yes, if the leak is small and coming from the drain valve, but it isn’t recommended.
