An experimental investigation were driven to catch all working parameters of an Air Source Heat Pump such as temperature differences between refrigerant working states and evaporator respectively condenser environment temperatures. Heat Pump compressor were monitored to know inlet and outlet refrigerant temperatures to build working diagram of the heat pump in heating configuration. At condenser, a plate heat exchanger is used to discharge the energy from refrigerant to water, liquid used in secondary circuit. Heat exchanger temperatures of refrigerant and water were monitored to drive the working diagram of the heat exchanger equipment. Current consumption of Heat Pump were registered together with heat exchanger secondary circuit temperature differences and his water flow to estimate Seasonal Performance Factor during experiment.