The answer to 'when to replace water line replacement' is that most experts recommend replacing your home's water lines every 20-50 years, depending on the material. Older galvanized steel or lead pipes are more prone to corrosion and leaks, and should be replaced sooner. Newer copper, PEX, or PVC pipes can often last 40-50 years with proper maintenance.
Signs it may be time to replace your water lines include frequent leaks, low water pressure, discolored water, and visible pipe damage. Replacing the main water line or branch lines can be a significant investment, but it's important to address issues proactively to prevent major water damage and costly repairs down the line.