to diverter valve 60 upon receipt of this signal the diverter valve 60 is arranged so that water pumped from water storage tank 46 enters aperture a 39 and exits through aperture b 39 the water exits aperture b 39 and flows through all of the refrigerant to water heat exchangers 38a c the heated water is then returned to the water storage tank 46 simultaneously control 100 sends a signal on line 64 to reversing valve 36 upon receipt of this signal reversing valve 36 is positioned so the flow of heated refrigerant enters aperture a and exits aperture d refrigerant also enters aperture c and exits aperture b in operation compressed refrigerant exits through the discharge line 44 of compressor 40 flowing through the entire series of refrigerant to water heat exchangers 38a c because the diverter valve 60 has directed the flow of water through the entire series of refrigerant to water heat exchangers 38a c the water is maintained in contact with the heated refrigerant for a maximum period the refrigerant continues to flow through the system entering reversing valve 36 through aperture a the reversing valve 36 is positioned so heated refrigerant enters aperture a and exits through aperture d the refrigerant continues on its designated path flowing to the indoor coil 32 when there is only a demand for water heating control 100 does not actuate blower 34 thus no significant gain or loss of heat occurs as the refrigerant flows through the indoor coil 32 the refrigerant flows through the indoor check valve 30 and outdoor throttling device.