How long does a water heater last and how can I tell its age?
Quick answer: A typical tank water heater lasts about 8 to 12 years, with our hard Minnesota water sometimes shortening that through sediment buildup. An inspector estimates age from the serial number on the manufacturer label and checks for corrosion, leaks, proper venting, and a working temperature-pressure relief valve. Knowing a water heater is near end of life lets you anticipate replacement, and finding active leaks or unsafe venting is an important safety item to address before closing.
The serial number usually encodes the manufacture date, letting an inspector determine the unit's age even when it is not obvious. Combined with visible condition, this gives a reliable read on how much service life likely remains.
Sediment and corrosion are the main enemies. Mineral buildup from hard water reduces efficiency and accelerates tank failure, while rust at fittings or the tank base can signal a leak that will eventually fail, sometimes suddenly.
Safety items include proper venting on gas units and a functioning temperature and pressure relief valve with an appropriate discharge pipe. Inspectors flag missing or improper TPR discharge lines because they are an important safety feature that is inexpensive to correct.
