The answer to 'when to replace water line' is that water lines should typically be replaced every 20-50 years, depending on the material and local conditions. Older galvanized steel or lead pipes are more prone to corrosion, leaks, and mineral buildup over time, while modern PEX or copper pipes can last longer with proper installation and maintenance.
Signs it's time to replace your water line include frequent leaks, low water pressure, discolored water, and a noticeable increase in water bills. If you notice any of these issues, it's best to have a professional plumber inspect your home's plumbing and recommend the best course of action.