Taco Zone Sentry zone valves provide on/off, normally closed control in closed hydronic systems. The unique patented technology in the Zone Sentry utilizes a microcircuit based logic to control a gear driven electronic actuator which drives a ball valve based body design. The valves can be used in a wide variety of heating and condensing cooling applications, primarily designed for use with baseboad, fan coils, radiators, convectors, air handlers, heat pumps and radiant applications.