How Long Do Water Heaters Last — and What Shortens Their Life?

Corrosion. A steel tank holds hot water under pressure for a decade, and the glass lining inside always has microscopic gaps. The anode rod — a magnesium or aluminum rod hanging inside the tank — corrodes preferentially, protecting the steel. Once the rod is consumed (typically 3–5 years), the tank itself starts rusting from the inside, silently.

Central Iowa's relatively hard water adds a second wear mechanism: sediment. Minerals settle on the tank bottom, insulating the burner from the water. The heater runs longer, the bottom overheats, and you'll often hear popping or rumbling — the sound of water flashing to steam under the sediment layer.

• Rusty or brown hot water (cold runs clear) — the tank interior is corroding.
• Rumbling, popping, or crackling — heavy sediment buildup.
• Moisture or drips around the base — a weeping tank rarely improves; small leaks precede failures.
• Running out of hot water faster — sediment is displacing capacity, or a heating element/burner is failing.
• Age past 10 years — even without symptoms, a tank in a finished basement past its expected life is a flood risk worth planning around rather than reacting to.

Two things, both inexpensive relative to a failure: an annual flush to remove sediment, and an anode rod check every couple of years with replacement when it's consumed. Add a quick test of the temperature-and-pressure relief valve — the safety device that prevents dangerous over-pressure — and you've covered the maintenance that matters. These checks fold naturally into a whole-home maintenance visit.