The Harmosol controls the temperature of the water automatically by using temperature sensors. The automatic temperature controller measures and regulates the difference between the temperature of the solar panels and the water temperature. The standard setting is  a difference of 4°C. When the difference increases, the controller sends signals to the electric valve, after which the temperature of the water will increase as well.

The Harmosol Plus is especially designed for measuring and regulating high temperatures. Since the swimming pool will be damaged when the temperature reaches higher than 32°C, the Harmosol Plus will stop the water from circulating through the solar panels. The Harmosol Plus ensures a pleasant water temperature, even when the sun shines at its brightest.