A valve (100) for controlling a flow of a medium in a heating and/or cooling system of a motor vehicle comprises a valve housing (110), which has at least one first channel (140), and a regulating wheel (170), which is provided to open and close the first channel. For this purpose, the regulating wheel is arranged at a first end of a rotatably mounted drive shaft (180), which extends from the regulating wheel through an axial opening (160) of the valve housing into a spring chamber (230) arranged in the valve housing. A second end of the drive shaft arranged in the spring chamber has a spur gear (190). Furthermore, a spring (240), the first end of which is supported on the valve housing and the second end of which is supported on the spur gear, is arranged in said spring chamber.