A device for controlling actuation of valves of a liquid treatment apparatus such as a filter or a water conditioning apparatus during the reconditioning operation such as washing the filter apparatus or regenerating the water conditioning apparatus characterized by a compound cam unit having at least two cam surfaces formed by a center member and a segment member which may be relatively rotated and adjusted to simultaneously adjust the length of the two cam surfaces. To rotate the cam unit, a motor drives a pinion which is yieldingly mounted for engagement with a driven gear of the cam unit which driven gear has a cut-out segment for receiving the pinion when the cam unit is in a neutral or service position. To shift the cam unit from the service position into an operating position, the device includes a shifting means which may be a pivoting lever operated by a calendar device or a solenoid engaging a groove on the cam unit when actuated by a sensed signal.