How long does a water heater last?

By Dana Whitlock. Updated October 2026.

Water heaters don't announce retirement. They leak. Most gas tanks get there somewhere between 10 and 15 years. The Department of Energy's 2024 water heater analysis puts the average gas storage tank at about 14.5 years, with a sensitivity range of 12.5 to 16.5 years. Older, more conservative charts land lower, at 10 years in a 2007 builders' study and 6 to 12 years for conventional water heaters on one inspector chart. The spread is mostly about water. Hard water, high water pressure and skipped maintenance shorten a tank's life, and a well-kept tank in soft water can outlast every figure here. Use the age as a starting point, then look at the tank itself. The steel shell decides when the heater is finished.

What wears out

The anode rod

Every glass-lined steel tank has a sacrificial anode rod, usually magnesium or aluminum, that corrodes so the tank doesn't. A.O. Smith says its life depends on water chemistry, how much hot water you use, and whether you have a softener. Once the rod is used up, the water goes to work on the tank wall. The manufacturer's advice is to check it yearly and replace it when several inches of the core wire show.

Sediment on the bottom

Minerals settle out of heated water and collect on the floor of the tank, right over the burner. That layer insulates the water from the flame, so the burner runs longer to heat the same amount of water and the steel under the sediment runs hotter. Over the years the bottom of the tank takes the beating, and that is where many tanks eventually leak. You often hear it first, as popping.

The tank shell and fittings

The steel tank can't be repaired once it rusts through. Leaks from the tank body are the end of the heater. Leaks from fittings, the drain valve or the relief valve are a different story, because those parts can be replaced. Find out exactly where the water is coming from before deciding anything.

Gas controls and venting

The gas control valve, thermocouple or flame sensor, igniter and burner all wear, and the vent can rust or come loose. These are repairable parts, but none of them are homeowner work. Diagnosis and replacement are a job for a licensed plumber.

Signs it's near the end

• Water pooling under the tank or rust streaks running down the jacket.
• Rusty or brown hot water while the cold water runs clear.
• Popping, rumbling or crackling as the burner runs, a common sign of heavy sediment.
• Hot water running out sooner than it used to, with no change in how you use it.
• A rotten egg smell in the hot water only, which often points to a reaction with the anode rod.
• The relief valve dripping or discharging often.
• An age past the DOE average of about 14.5 years, read from the serial number on the rating plate.

What helps it last

• Drain a few gallons from the drain valve, or flush the tank, as your owner's manual describes. A.O. Smith says most tank heaters need flushing at least once a year, more often in hard water areas.
• Have the anode rod checked every year or two and replaced when it is mostly consumed. Many owners have a plumber do this during a flush.
• Keep the thermostat at about 120 degrees Fahrenheit, the setting A.O. Smith recommends to balance scald risk against bacteria growth.
• Look at the relief valve discharge pipe and the floor around the tank every month or so for drips or rust.
• Keep the area around the heater clear of boxes, laundry and anything flammable so the burner gets combustion air.
• If the relief valve drips, ask a plumber to check your water pressure and whether you need a thermal expansion tank.

Repair or replace?

Start with the leak test. Water coming from the tank body means a new heater. If the tank is dry, weigh the repair against what's left of its life, using cost per remaining year. Divide the repair price by the years you can reasonably expect the tank to keep going, then divide the replacement cost shown above by the 12 to 15 years a new tank should give you. When the repair works out to more per year, replace. The 50 percent rule is a rougher version of the same idea. A repair costing more than about half the price of a new heater, on a tank past the middle of its life, usually means replacing. A thermocouple or igniter on a six-year-old tank almost always deserves the repair. The same part on a 14-year-old tank with sediment noise and rusty water usually doesn't, because the tank is likely to fail soon after.

Common symptoms

• Why does my hot water run out so fast
• Why is my hot water rusty
• Why is my water heater leaking from the bottom
• Why is my water heater not making hot water
• Why won't my water heater pilot stay lit
• Why is my water heater making a popping noise
• Why is my water heater relief valve leaking
• Why does my hot water smell like rotten eggs