What it can look like at home
A zone is an area served or controlled separately from another area. In hydronic systems, zones may use separate loops or controls; in forced-air systems, zoning may involve dampers and controls; ductless heads can also create room-by-room operation.
Why it can happen
Zoning divides a home into areas with separate controls or distribution paths. Depending on the system, that can involve dampers, valves, circulators, thermostats, sensors, or more than one piece of equipment. A zoning concern needs to be separated from a general heating or cooling failure.