The answer to 'hydro jetting won't flush' is that the hydro jetting process may not be fully clearing the blockage in your plumbing system. Hydro jetting uses high-pressure water to break up and flush out clogs, but if the blockage is severe or located in a difficult-to-reach area, the jetting may not be able to fully clear it.
Some common causes of hydro jetting not flushing properly include a very stubborn clog, a blockage in the main sewer line, or an issue with the hydro jetting equipment itself. Symptoms may include slow or no drainage, gurgling sounds, or sewage backups. If hydro jetting doesn't resolve the issue, you may need to call a professional plumber to further investigate and use additional techniques to clear the blockage.