A heat pump water heater comprising: a compressor configured to compress a refrigerant; a first water-refrigerant heat exchanger configured to exchange heat between the refrigerant and water; a second water-refrigerant heat exchanger configured to exchange heat between the refrigerant and water; refrigerant paths (10, 17, 18, 19, 20, 21) capable of forming a refrigerant circuit, the refrigerant circuit supplying the refrigerant compressed by the compressor to the first water-refrigerant heat exchanger, the refrigerant circuit supplying the refrigerant that has passed through the first water-refrigerant heat exchanger to the second water-refrigerant heat exchanger; and water channels including a flow channel, the flow channel leading hot water that has passed through the second water-refrigerant heat exchanger to the first water-refrigerant heat exchanger, the heat pump water heater being able to perform a heating operation, the hot water heated in the second water-refrigerant heat exchanger being fed to the first water-refrigerant heat exchanger in the heating operation, the hot water further heated in the first water-refrigerant heat exchanger being supplied to a downstream side of the water channels in the heating operation, the first water-refrigerant heat exchanger being able to be replaced without replacing the second water-refrigerant heat exchanger, the compressor including a first inlet from which the refrigerant is drawn in, and a first outlet from which the refrigerant drawn in from the first inlet is discharged, the heat pump water heater being characterized in that the compressor further includes a second inlet from which the refrigerant is drawn in, and a second outlet from which the refrigerant drawn in from the second inlet is discharged, and that the refrigerant paths (10, 17, 18, 19, 20, 21) include a path that leads the refrigerant discharged from the first outlet to the first water-refrigerant heat exchanger, a path that leads the refrigerant that has passed through the first water-refrigerant heat exchanger to the second inlet, and a path that leads the refrigerant discharged from the second outlet to the second water-refrigerant heat exchanger. a compressor configured to compress a refrigerant; a first water-refrigerant heat exchanger configured to exchange heat between the refrigerant and water; a second water-refrigerant heat exchanger configured to exchange heat between the refrigerant and water; refrigerant paths (10, 17, 18, 19, 20, 21) capable of forming a refrigerant circuit, the refrigerant circuit supplying the refrigerant compressed by the compressor to the first water-refrigerant heat exchanger, the refrigerant circuit supplying the refrigerant that has passed through the first water-refrigerant heat exchanger to the second water-refrigerant heat exchanger; and water channels including a flow channel, the flow channel leading hot water that has passed through the second water-refrigerant heat exchanger to the first water-refrigerant heat exchanger, the heat pump water heater being able to perform a heating operation, the hot water heated in the second water-refrigerant heat exchanger being fed to the first water-refrigerant heat exchanger in the heating operation, the hot water further heated in the first water-refrigerant heat exchanger being supplied to a downstream side of the water channels in the heating operation, the first water-refrigerant heat exchanger being able to be replaced without replacing the second water-refrigerant heat exchanger, the compressor including a first inlet from which the refrigerant is drawn in, and a first outlet from which the refrigerant drawn in from the first inlet is discharged, the heat pump water heater being characterized in that the compressor further includes a second inlet from which the refrigerant is drawn in, and a second outlet from which the refrigerant drawn in from the second inlet is discharged, and that the refrigerant paths (10, 17, 18, 19, 20, 21) include a path that leads the refrigerant discharged from the first outlet to the first water-refrigerant heat exchanger, a path that leads the refrigerant that has passed through the first water-refrigerant heat exchanger to the second inlet, and a path that leads the refrigerant discharged from the second outlet to the second water-refrigerant heat exchanger.