The answer to 'water line replacement overflowing' is that the most common cause is an issue with the newly installed water line. This can happen if the line was not properly connected or sealed, resulting in leaks that cause water to overflow. Symptoms may include water pooling around the new line, damp walls or floors, or a noticeable drop in water pressure.
In this situation, it's best to call a professional plumber to diagnose and fix the problem. Attempting to DIY a water line replacement can be risky and lead to further damage if not done correctly. A qualified plumber will be able to inspect the new line, identify the source of the leak, and make the necessary repairs to stop the overflow.