A major ratio between the heat transfer area and volume unit puts the soldered plate heat Exchanger among the most efficient heat exchangers and makes it the key element in the heating systems. The plate heat exchanger is also increasingly used for direct heating of drinking water. That is the main reason for our plate heat exchanger design, which does not contain copper soldering foil since it has a worse corrosion resistance compared to stainless steel heating plates. For this purpose, we tested mechanical properties of the heat exchanger made using exclusively stainless-steel materials. The measured values were used to predict the sustainability of the heat exchanger when used in real circumstances. In addition, we made measuring line on which we measured the dynamics of opening of electromagnetic valves and we analized transient temperature field on the heat exchanger plates with an infrared camera.