A leaking water heater is typically a sign of corrosion, structural failure, or excessive pressure buildup. Here are the most common causes of leaks:
Internal Corrosion – Over time, the steel tank of a water heater can corrode, especially if the anode rod has deteriorated. Once rust eats through the tank, water will begin to leak, and there’s no way to repair it permanently.
Sediment Buildup – Hard water can lead to sediment buildup at the bottom of the tank. This sediment can cause overheating, which weakens the tank and eventually leads to leaks.
Excessive Water Pressure – If the water pressure inside the tank is too high, it can strain the tank walls, leading to cracks and leaks.
Faulty Temperature & Pressure (T&P) Valve – The T&P valve is designed to release excess pressure, but if it malfunctions, pressure can build up and cause leaks or even a tank rupture.
Physical Damage – External impacts, such as accidental damage during maintenance or installation, can weaken the tank and cause leaks.
Once a water heater starts leaking, its remaining lifespan is unpredictable. It may last a few days, weeks, or even months, but there’s also a risk that the leak could escalate into a sudden and catastrophic failure at any moment. Here’s why you should act quickly:
A small leak can grow rapidly. What starts as a minor drip can suddenly become a major rupture, leading to gallons of water flooding your home or building.
Leaks can cause water damage. Even a slow leak can cause mold growth, wood rot, and structural damage if left unaddressed.
Higher risk of complete tank failure. The longer you delay replacing the unit, the greater the risk of total tank failure, which can lead to expensive repairs, water damage, and liability concerns.
If you notice a leak coming from your water heater, take these steps immediately:
Turn Off the Water Supply – Locate the cold-water shutoff valve (usually found near the top of the water heater) and turn it off to prevent further leaking.
Shut Off the Power or Gas Supply – For electric water heaters, turn off the power at the breaker panel. For gas water heaters, switch the gas supply off.
Check the Source of the Leak – If the leak is coming from a valve or connection, it may be repairable. However, if the tank itself is leaking, replacement is the only solution.
Drain the Tank (If Necessary) – If the leak is severe, draining the tank can help prevent further water damage. Attach a garden hose to the drain valve and direct the water to a safe location.
Call a Professional Plumber – A licensed plumber can assess the situation and recommend whether repairs are possible or if a full replacement is needed.
While it might be tempting to wait and see how long the leaking water heater will last, this is a high-risk decision. A leaking tank is a clear indicator that the unit has reached the end of its lifespan, and failure is imminent. Delaying replacement increases the chances of:
Major flooding and property damage
Costly emergency repairs
Mold and mildew growth
Potential liability if water damage affects other units in a multi-family property
A leaking water heater is not something to ignore. While it may continue functioning for a short period, it could also fail suddenly, leading to extensive water damage. The safest and most cost-effective solution is to replace the unit as soon as possible to avoid unnecessary risks
Notifications
