To provide a low-cost motor operated valve for a water circuit.

A butterfly valve 1 is adopted as a control valve for the water circuit to considerably reduce cost compared with a ball valve used as the control valve for the water circuit, and a common body 4 with the butterfly valve 1 and a motor actuator 2 integrally formed is used to reduce the number of parts and cost. Further, a detecting element or the like for detecting the rotating position of a valve element 17 is dispensed with by constituting to stop a motor by mechanical locking.