A system for air-conditioning and hot-water supply and configured to selectively perform a cooling operation and heating operation, comprising: an outdoor unit having a compressor, an outdoor heat exchanger, a switching valve, an accumulator and an outdoor fan; a plurality of indoor units (120a, 120b) each of which is connected to the outdoor unit and includes an indoor heat exchanger (121a, 121b); a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the plurality of indoor units (120a, 120b) and including a refrigerant-water heat exchanger; and a controller configured to monitor a request for hot-water supply from the hot-water supply unit; wherein the outdoor unit, the indoor units (120a, 120b), and the hot-water supply unit are connected by a gas main pipe and a liquid main pipe; during the heating operation, the outdoor unit forms a refrigerant circuit for heating in which the outdoor heating exchanger, the switching valve, the accumulator, the compressor, and the switching valve are sequentially connected in this order from the liquid main pipe side toward the gas main pipe; during the cooling operation, the outdoor unit forms a refrigerant circuit for cooling in which the switching valve, the accumulator, the compressor, the switching valve, and the outdoor heating exchanger are sequentially connected in this order from the gas main pipe side toward the liquid main pipe; and the hot-water supply unit has a function of transferring heating energy or cooling energy from the outdoor unit to water so as to perform the heating operation or the cooling operation thereon; characterised in that the controller is further configured to continue a cooling operation after said request has occurred and until a predetermined condition is satisfied where the request for hot-water supply has occurred during said cooling operation at at least one of the plurality of indoor units (120a, 120b), and then to start a heating operation. an outdoor unit having a compressor, an outdoor heat exchanger, a switching valve, an accumulator and an outdoor fan; a plurality of indoor units (120a, 120b) each of which is connected to the outdoor unit and includes an indoor heat exchanger (121a, 121b); a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the plurality of indoor units (120a, 120b) and including a refrigerant-water heat exchanger; and a controller configured to monitor a request for hot-water supply from the hot-water supply unit; wherein the outdoor unit, the indoor units (120a, 120b), and the hot-water supply unit are connected by a gas main pipe and a liquid main pipe; during the heating operation, the outdoor unit forms a refrigerant circuit for heating in which the outdoor heating exchanger, the switching valve, the accumulator, the compressor, and the switching valve are sequentially connected in this order from the liquid main pipe side toward the gas main pipe; during the cooling operation, the outdoor unit forms a refrigerant circuit for cooling in which the switching valve, the accumulator, the compressor, the switching valve, and the outdoor heating exchanger are sequentially connected in this order from the gas main pipe side toward the liquid main pipe; and the hot-water supply unit has a function of transferring heating energy or cooling energy from the outdoor unit to water so as to perform the heating operation or the cooling operation thereon; characterised in that the controller is further configured to continue a cooling operation after said request has occurred and until a predetermined condition is satisfied where the request for hot-water supply has occurred during said cooling operation at at least one of the plurality of indoor units (120a, 120b), and then to start a heating operation.