The answer to 'how do I know if I need to replace my water heater' is that you typically need to replace your water heater every 8-12 years, or sooner if you notice any of the following signs: your water heater is making strange noises, the water isn't getting hot enough, or you're seeing leaks or rust around the unit.
Over time, the internal components of a water heater can wear down, leading to decreased efficiency and potential failures. It's important to monitor your water heater and replace it before it completely stops working to avoid the hassle and cost of an unexpected breakdown. Calling a professional plumber to inspect your water heater and provide recommendations is the best way to determine if replacement is needed.