A hot water apparatus , in particular a heat pump, comprising - a hot water storage tank having a storage capacity and a measuring unit , in particular a temperature sensor, for determining a temperature at a location within the hot water storage tank , the hot water storage tank having a water inlet and a water outlet , wherein upon and/or following removal of a draw-off volume from the water outlet an inflow volume can flow through the water inlet into the hot water storage tank , - a heat exchanger for heating water in the hot water storage tank , and - a control unit that is arranged to - control the heat exchanger such that the water in the hot water storage tank has a first set temperature or a second set temperature , wherein the first set temperature is lower than the second set temperature, - identify draw-off events , wherein - a draw-off event is identified on the basis of a determined temperature drop , - a predefined reference volume is assigned to a draw-off event , - to set the first set temperature if, in a predetermined period of time, the summed reference volumes of the draw-off events are greater than the storage tank volume, and - to set the second set temperature if, in the predetermined period of time, the summed reference volumes of the draw-off events are less than the storage tank volume. - a hot water storage tank having a storage capacity and a measuring unit , in particular a temperature sensor, for determining a temperature at a location within the hot water storage tank , the hot water storage tank having a water inlet and a water outlet , wherein upon and/or following removal of a draw-off volume from the water outlet an inflow volume can flow through the water inlet into the hot water storage tank , - a heat exchanger for heating water in the hot water storage tank , and - a control unit that is arranged to - control the heat exchanger such that the water in the hot water storage tank has a first set temperature or a second set temperature , wherein the first set temperature is lower than the second set temperature, - identify draw-off events , wherein - a draw-off event is identified on the basis of a determined temperature drop , - a predefined reference volume is assigned to a draw-off event , - to set the first set temperature if, in a predetermined period of time, the summed reference volumes of the draw-off events are greater than the storage tank volume, and - to set the second set temperature if, in the predetermined period of time, the summed reference volumes of the draw-off events are less than the storage tank volume. - control the heat exchanger such that the water in the hot water storage tank has a first set temperature or a second set temperature , wherein the first set temperature is lower than the second set temperature, - identify draw-off events , wherein - a draw-off event is identified on the basis of a determined temperature drop , - a predefined reference volume is assigned to a draw-off event , - a draw-off event is identified on the basis of a determined temperature drop , - a predefined reference volume is assigned to a draw-off event , - to set the first set temperature if, in a predetermined period of time, the summed reference volumes of the draw-off events are greater than the storage tank volume, and - to set the second set temperature if, in the predetermined period of time, the summed reference volumes of the draw-off events are less than the storage tank volume. <EOS>