The answer to 'water heater replacement frequency' is that most water heaters need to be replaced every 8-12 years on average. The lifespan of a water heater can vary depending on factors like the quality of the unit, how well it's maintained, and the water quality in your home. With proper care and maintenance, some water heaters may last up to 15 years, but it's generally recommended to replace them every decade or so to avoid costly leaks or breakdowns.
It's a good idea to have your water heater inspected annually by a professional plumber, who can check for any signs of wear and tear and let you know if replacement is needed soon. They can also provide guidance on the right size and type of water heater for your home's needs.