The answer to 'when to replace water heater installation' is that most water heaters need to be replaced every 8-12 years, depending on the type and usage. Signs it's time to replace your water heater include strange noises, rusty water, and frequent repairs. Older water heaters also become less energy-efficient over time, leading to higher utility bills.
If your water heater is reaching the end of its lifespan or experiencing issues, it's best to have a licensed plumber inspect it and provide a recommendation on whether to repair or replace it. Replacing a water heater is a complex job that requires specialized knowledge and tools, so it's generally not recommended as a DIY project.