METHOD AND CONTROLLER TO OPERATE A DOMESTIC HOT WATER SYSTEM AND DOMESTIC HOT WATER SYSTEM

Method to operate a domestic hot water system (10), the domestic hot water system (10) having a tank (11) to store hot potable water, the domestic hot water system (10) having at least one remote location (12) being remote from the tank (11) at which water stored within the tank (11) can be provided to a respective water consumer (13), wherein the respective remote location (12) is connected to the tank (11) through a respective water pipe (14), wherein a temperature sensor (16) is assigned to the respective remote location (12) or to the respective water pipe (14) guiding the water stored within the tank (11) to the respective remote location (12), wherein the method comprises the following steps: Measuring a respective temperature at a respective remote location (12) or at the respective water pipe (14) with the respective temperature sensor (16). Determining from the respective temperature measured by the respective temperature sensor (16) a water usage event at the respective remote location (12). Determining during a determined water usage event a temperature profile (24) from the temperature measured by the respective temperature sensor (13). Determining from the temperature profile (24) determined during the water usage event a risk factor of microbiological growth at the respective remote location (12) or of microbiological growth within the respective water pipe (14). Initiating and executing a disinfection cycle for the respective remote location (12) or the respective water pipe (14) if the respective risk factor of microbiological growth is above a respective risk threshold. (Figure 1)