US Patent 6981383 Zone damper fault detection in an HVAC system

A zoned HVAC system is provided with a series of dampers. A control for the dampers causes the dampers to each move between open and closed positions while monitoring a system condition. The system condition is selected to be one that should change as the damper moves between open and closed positions. If the system condition does not change as the control orders the damper to move between the open and closed positions, the particular damper is identified as a potentially faulty damper.