The answer to 'when to replace water heater' is that you should typically replace your water heater every 8-12 years, or sooner if it starts showing signs of wear and tear. Water heaters have a limited lifespan, and over time the tank and components can corrode, leading to leaks, reduced efficiency, and even complete failure. Factors like the quality of the water heater, how often it's used, and how well it's maintained can also affect its lifespan.
It's a good idea to have your water heater inspected annually by a professional plumber, who can check for any issues and let you know if replacement is recommended. Some common signs it's time to replace your water heater include rusty water, strange noises, and a significant drop in hot water output.