The principle of operation of solar collectors is based on the conversion of solar radiation into heat. Solar collectors are flat panels containing a cable filled with non-freezing propylene glycol solution. Its circulation is forced by a circulation pump, the operation of which is dependent on the controller. The collector is connected by two flexible pipes with a coil located in the heat exchanger. During its circulation, the glycol solution transfers the heat from the solar collectors to the coil, which transfers the heat to the water inside the exchanger. The collectors can be installed both on the roof of a residential or commercial building and directly on the ground.