The answer to 'why is my septic tank won't flush' is that there could be a blockage or obstruction in the septic system. A clogged septic tank or drain field can prevent proper flushing and drainage, causing backups and slow draining. Common causes include excessive use, buildup of solids, tree roots, or damage to the system.
If your septic tank isn't flushing properly, first check for signs of a blockage like slow draining sinks, gurgling sounds, or sewage odors. You can also try plunging the toilet or running a garden hose down the main drain to see if that clears the blockage. However, if the problem persists, it's best to call a professional septic service to inspect and properly diagnose the issue. Attempting to fix a major septic system problem on your own can lead to further damage or health hazards.