How long does an A. O. Smith water heater usually last?

An A. O. Smith water heater usually lasts 8 to 12 years for a standard glass-lined steel tank model and up to 15 to 20 years for premium or tankless models, depending on maintenance, water quality, and model tier. The basic 6-year warranty Signature and ProLine tank models typically last 8 to 10 years in average conditions. Models with 9-year or 12-year warranties, which have larger or dual anode rods and thicker glass lining, often last 12 to 15 years when properly maintained. Factors that affect lifespan include hard water, which causes sediment buildup and accelerates corrosion, whether the tank is flushed annually, whether the anode rod is inspected and replaced every 3 to 5 years, water pressure, and thermostat setting. Keeping the temperature at 120 degrees reduces stress. Tankless A. O. Smith water heaters, which do not store water and avoid tank corrosion, usually last 15 to 20 years, provided they are descaled annually in hard water areas. Heat pump hybrid Voltex models have similar lifespans to tankless when maintained. Signs that an A. O. Smith water heater is nearing end of life include rusty water, rumbling or popping noises, water pooling around the base, insufficient hot water, and frequent tripping of the reset button. Proactive replacement before catastrophic tank failure is recommended once the unit exceeds 10 years and shows symptoms.