The answer to 'repiping won't flush' is that there are several common causes, including a blockage in the plumbing system, a problem with the water pressure, or an issue with the toilet itself. Symptoms may include slow or incomplete flushing, water not draining properly, or a gurgling sound in the pipes.
To troubleshoot the issue, you can start by checking for any obvious clogs or blockages in the toilet or drain lines. If that doesn't solve the problem, you may need to check the water pressure or consider a more comprehensive repiping project. While some minor plumbing repairs can be done as a DIY project, it's generally best to call a professional plumber for any major issues or if you're not comfortable working on the plumbing system.