The answer to 'when to replace faucet installation' is that you should typically replace your faucet every 10-15 years, or sooner if it's leaking, not functioning properly, or you want to update the style. Faucets are subject to a lot of daily use and wear and tear, so they don't last forever. Over time, the internal components like washers, seals, and springs can wear out, leading to leaks, drips, and other issues.
If your faucet is more than 10 years old and starting to show signs of wear, it's a good idea to consider replacing it. This will help prevent bigger plumbing problems down the line. When replacing a faucet, it's best to hire a professional plumber to ensure it's installed correctly and working properly.