The answer to 'why is my zone control system short cycling' is that there are several common causes, including issues with the thermostat, dampers, or the control board. Short cycling occurs when the HVAC system turns on and off rapidly, which can be caused by a malfunctioning zone control system. This can lead to inefficient heating and cooling, and potentially damage the equipment over time.
Some common symptoms of a short cycling zone control system include uneven temperatures in different rooms, the system turning on and off frequently, and higher-than-normal energy bills. To troubleshoot the issue, you may need to check the thermostat settings, inspect the zone dampers for proper operation, and ensure the control board is functioning correctly. In some cases, the solution may be as simple as adjusting the thermostat or cleaning the zone dampers. However, if the issue persists, it's best to call a professional HVAC technician to diagnose and repair the problem.