The answer to 'when to replace supply line' is that you should replace your plumbing supply lines every 5-10 years, or sooner if you notice any signs of wear or damage. Supply lines are the flexible hoses that connect your water fixtures (like sinks, toilets, and washing machines) to the main water supply. Over time, these lines can become brittle, develop cracks, or start to leak, which can lead to water damage and costly repairs.
It's generally a good idea to replace supply lines as a preventative measure, even if you haven't noticed any issues. This helps avoid unexpected leaks and floods down the line. When replacing supply lines, be sure to use high-quality, braided stainless steel or reinforced plastic lines, as these are more durable than the standard rubber or plastic hoses.