A heat pump heater a) comprising a working medium flowing through a condenser in a closed working medium circuit, b) wherein the condenser has at least one first heat exchanger and at least one second heat exchanger, through which the working medium flows in succession on their respective primary side, wherein the first heat exchanger is arranged upstream of the second heat exchanger with respect to the working medium, c) wherein a liquid, in particular water, is able to flow through the first heat exchanger on its secondary side, which liquid is circulated through a first hydraulic switch, preferably by means of a first pump, d) wherein a liquid, in particular water, is able to flow through the second heat exchanger on its secondary side, which liquid is circulated through a second hydraulic switch, preferably by means of a second pump, e) wherein the first heat exchanger and the second heat exchanger are designed to transfer energy from the working medium to the liquid and thereby heat the liquid flowing through, f) wherein the heat pump heater is designed such that the liquid in the first hydraulic switch has a higher temperature than the liquid in the second hydraulic switch, g) having at least one first heating and/or hot water preparation device, in particular comprising one or more radiators and/or a hot water tank and/or a continuous flow heater, and comprising at least one second heating and/or hot water preparation device, in particular underfloor heating, wherein the first heating and/or hot water preparation device is intended for higher flow temperatures than the second heating and/or hot water preparation device, h) comprising a hydraulic system filled with liquid, in particular water, wherein the hydraulic system is designed for the liquid to flow through the hydraulic system, i) wherein the hydraulic system hydraulically connects the first heating and/or hot water preparation device and the second heating and/or hot water preparation device and connects the first hydraulic switch and the second hydraulic switch to one another, j) wherein the hydraulic system has a mixing valve, in particular a motor-operated mixing valve, for changing and/or adjusting the hydraulic system as a function of the current heating load of the first heating and/or hot water preparation device and/or the second heating and/or hot water preparation device. a) comprising a working medium flowing through a condenser in a closed working medium circuit, b) wherein the condenser has at least one first heat exchanger and at least one second heat exchanger, through which the working medium flows in succession on their respective primary side, wherein the first heat exchanger is arranged upstream of the second heat exchanger with respect to the working medium, c) wherein a liquid, in particular water, is able to flow through the first heat exchanger on its secondary side, which liquid is circulated through a first hydraulic switch, preferably by means of a first pump, d) wherein a liquid, in particular water, is able to flow through the second heat exchanger on its secondary side, which liquid is circulated through a second hydraulic switch, preferably by means of a second pump, e) wherein the first heat exchanger and the second heat exchanger are designed to transfer energy from the working medium to the liquid and thereby heat the liquid flowing through, f) wherein the heat pump heater is designed such that the liquid in the first hydraulic switch has a higher temperature than the liquid in the second hydraulic switch, g) having at least one first heating and/or hot water preparation device, in particular comprising one or more radiators and/or a hot water tank and/or a continuous flow heater, and comprising at least one second heating and/or hot water preparation device, in particular underfloor heating, wherein the first heating and/or hot water preparation device is intended for higher flow temperatures than the second heating and/or hot water preparation device, h) comprising a hydraulic system filled with liquid, in particular water, wherein the hydraulic system is designed for the liquid to flow through the hydraulic system, i) wherein the hydraulic system hydraulically connects the first heating and/or hot water preparation device and the second heating and/or hot water preparation device and connects the first hydraulic switch and the second hydraulic switch to one another, j) wherein the hydraulic system has a mixing valve, in particular a motor-operated mixing valve, for changing and/or adjusting the hydraulic system as a function of the current heating load of the first heating and/or hot water preparation device and/or the second heating and/or hot water preparation device.