The invention discloses a 
water heating machine system of a heat 
recovery multi-gang 
heat pump air conditioner, which comprises a compressor, a three-way valve, an outdoor 
heat exchanger, an indoor 
heat exchanger, and a plurality of electronic expansion valves, 
branch pipes and electromagnetic valves. One end of the three-way valve is communicated with a high-pressure air 
pipe of the compressor; the other end of the three-way valve is communicated with the outdoor 
heat exchanger, the electronic expansion valves, the 
branch pipes and the indoor heat exchanger in sequence; and the high-pressure air 
pipe and a high-pressure liquid 
pipe of the compressor are respectively connected with a 
water heating tank through the 
branch pipes and the electronic expansion valves. By using the 
water heating machine system, the breakover or the turning off of the electromagnetic valves is controlled through an 
electric control device to switch the communication of a low-pressure air pipe, the high-pressure air pipe and the indoor heat exchanger, so that the indoor heat exchanger can carry out 
refrigeration or heating, and the breakover or the turning off of the electromagnetic valves is controlled through the 
electric control device, so that the high-pressure air pipe and the water heating tank are subjected to the breakover or are turned off and the water heating tank can heat water. By adopting the way, through the whole 
system, the running of three basic 
modes, namely, air conditioner 
refrigeration, air conditioner heating and water heating, can be achieved simultaneously.