To reduce standby power in a heat source system equipped with a plurality of outdoor units.

The heat source system includes a plurality of heat source units 11 communicably connected. Each of the heat source units 11 includes compressors A and B, a control part 21 for controlling operation of the heat source unit 11 containing the compressors A and B, and switch parts 31, 411, and 421 for supplying/cutting off power to at least a part of the control part 21. A power feeding control means 40 supplies, when the compressors A and B of any of the heat source units 11 are in operation and the compressors A and B of other heat source units 11 are suspended, a power cut-off control signal to the switch parts 31, 411, and 421 in the power source unit 11 where compressors A and B are suspended, based on a predetermined power cut-off condition, and supplies a power supply control signal to the switch parts 31, 411, and 421 in the heat source unit 11 where power has been cut off by the cut-off control signal, based on a predetermined power supply condition.