These thesis presents the development of a defrosting valve in the refrigerator, which is not currently on the market. It defrosts ice that accumulates in the freezer. This consequently increases the energy efficiency of the refrigerator and the quality of foods in it. In addition, we save on electricity consumption. The design procedures, the numerical analysis of the valve and, in the end, the results of the measurements of the 4/2 way of the valve are shown.