Provided are a hot water heat pump and a method for controlling the same, wherein the installation cost and the installation space can be reduced, and the period of time necessary for increasing the temperature of a hot water system can be reduced. A hot water heat pump (1) is provided with a hot water heat pump main body (2) having a thermal output heat exchanger which acquires heat from a heat source system and outputs the heat; hot water systems (5, 6) which acquire heat from the thermal output heat exchanger; a three-way valve (4) provided on the outlet-side hot water system (6); and a control unit for controlling the hot water heat pump main body (2) and the three-way valve (4). The control unit controls the opening of the three-way valve (4) so that a part of the outlet-side hot water system (6) introduced from the thermal output heat exchanger is introduced toward the upstream side of the thermal output heat exchanger.