The answer to 'water heater replacement frequency' is that the typical lifespan of a water heater is 8-12 years, but this can vary depending on the type of heater, usage, and maintenance. Most manufacturers recommend replacing the water heater every 10 years to ensure it's operating efficiently and safely.
Factors that can affect the lifespan of a water heater include the quality of the unit, how often it's used, the water quality in your area, and how well it's been maintained through regular flushing and inspection. Proper maintenance, such as flushing the tank annually to remove sediment buildup, can help extend the life of your water heater.