The answer to 'zone control system making loud noise' is that a noisy zone control system is usually caused by a problem with the dampers or motors that regulate airflow to different zones in your home. Common symptoms include rattling, buzzing, or grinding noises coming from the vents or the control panel. This can be due to worn-out components, loose connections, or issues with the system's programming.
If the noise is coming from a specific zone, it may be a problem with that zone's damper or motor. If the noise is coming from the control panel, it could be an issue with the central control board or wiring. In some cases, the noise may be caused by airflow imbalances or leaks in the ductwork.