The answer to 'sewer repair won't flush' is that there are several common causes, including a clogged sewer line, a broken or collapsed sewer pipe, tree root intrusion, or a problem with the septic system. Symptoms may include slow draining sinks or tubs, gurgling sounds, and sewage backups.
In many cases, a sewer repair issue can be fixed with a professional sewer line cleaning or minor pipe repair. However, more extensive sewer line replacement or septic system maintenance may be required in some situations. It's best to call in a licensed plumber to properly diagnose and resolve the problem.