The Icma-s302 differential thermostat is a basic electronic device for adjusting and controlling solar thermal systems. It continuously monitors the water temperature in the collectors and the hot water temperature in the boiler. When the temperature in the collectors is higher than that in the boiler by the set number of degrees, it activates the circulation pump, allowing hot water to be transferred to the boiler's exchanger. This process enhances the efficiency of the solar collectors and ensures that hot water is always available for use.