The answer to 'how to fix zone control system' is that the first step is to diagnose the issue. This involves checking the thermostat, dampers, and control panel to identify any problems. Common issues include faulty wiring, malfunctioning dampers, or issues with the control board.
Once the problem is identified, you can take steps to fix it, such as replacing faulty components or adjusting the system settings. However, if the issue is more complex, it's best to call in a professional HVAC technician to diagnose and repair the system.