A refrigeration cycle device includes a heating unit, an air-heating expansion valve, an outdoor heat exchanger, an air-cooling expansion valve, an indoor evaporator, and a cooler-unit expansion valve, a cooler unit, and a refrigerant circuit switching unit. In a heating series cooler-unit mode, refrigerant is circulated in order of the heating unit, the air-heating expansion valve, the outdoor heat exchanger, the cooler-unit expansion valve, and the cooler unit. In a heating parallel cooler-unit mode, refrigerant is circulated in order of the heating unit, the air-heating expansion valve, and the outdoor heat exchanger, and refrigerant is circulated in order of the heating unit, the cooler-unit expansion valve, and the cooler unit.