The average lifespan of a water heater in the United States is approximately 8 to 12 years. This duration can vary significantly based on several factors, including the type of water heater, the quality of installation, and the maintenance routine followed by the homeowner.

The lifespan of a traditional tank-style water heater is generally shorter than that of a tankless water heater. Tank-style water heaters can last between 8 and 12 years, while tankless water heaters can typically last up to 20 years or more. The longevity of a tankless water heater is attributed to its lack of a storage tank, which reduces the risk of corrosion and sediment buildup.

Regular maintenance is crucial for extending the life of a water heater. This includes flushing the tank to remove sediment, checking for leaks, and ensuring that the temperature and pressure relief valve is functioning properly. According to the U.S. Department of Energy, water heater maintenance can improve efficiency and extend the appliance's lifespan by up to 30%.

Data from the U.S. Energy Information Administration (EIA) indicates that the average water heater in the U.S. is about 12 years old. This aligns with the general lifespan of traditional tank-style water heaters. Additionally, the EIA reports that the average annual energy consumption for water heating in a U.S. home is about 14% of total energy use, highlighting the importance of efficient water heating systems.

In conclusion, the average water heater lifespan in the United States is 8 to 12 years for tank-style units and up to 20 years for tankless units. Proper maintenance and regular checks are essential for maximizing the lifespan of a water heater.