Abstract: The invention relates to a pump and control unit for a solar heating installation system for a water tank, particularly for a swimming pool. The system contains a solar collector, a hydraulic circuit which includes an outward-flow pipe, a return-flow pipe, a pump, a derivative-action control unit and two sensors mounted on the outward-flow pipe and on the return-flow pipe, respectively. The pump, the control unit and the two sensors are integrated into a single case. The case is provided in its top wall with a transparent opening which faces the return-flow sensor and through which said sensor can be exposed to solar radiation, such that the pump may be automatically activated during periods of sunshine, i.e., when the solar collector is heating the water returning to the tank, and stopped due to lack of sunshine.