The paper presents selected issues relating to the energy analysis of the air heat pump for hot water. Experimental studies on a test stand made it possible to verify the operational parameters of the heat pump under actual conditions of use. The study shows that heating the water in the storage tank with the capacity of 130 dm3 from 25°C to 40°C took approximately 60 minutes and the water heating for another 5°C took 30 minutes longer. The heat pump process in the field of higher water temperature in the tank is less effective, thus heating the water in the tank above 50°C is less favorable economically.