A method for operating a water circulation system comprising the steps of: - Providing the water circulation system, comprising: - at least one feed line, - at least one return line, - at least one strand which connects the feed line to the return line, - at least one temperature control unit, which connects the feed line to the return line, whereby water can circulate in a flow direction from the at least one feed line, via the at least one strand and the at least one return line back to the feed line, - at least one consumer, which is arranged along the at least one strand and with which water can be removed from the circulation system, - at least one valve with which the flow rate of the water in the circulation system can be changed, - at least one temperature sensor (60,61,62), with which the water temperature in a line section can be detected, - at least one system controller with which the data of the at least one temperature sensor (60,61,62) can be processed and with which the at least one valve can be actuated; - Determining a first temperature (T 1); - Determining a second temperature (T 2); - Determining a lowering time; - Detecting the water temperature with the at least one temperature sensor (60,61,62); - Setting the first temperature (T 1) in the pipe section by setting a first flow rate (D 1) with the at least one valve; - Setting the second temperature (T 2) in the line section by setting a second flow rate (D 2) with the at least one valve during the lowering time; - Setting a time window; - Setting a minimum temperature difference; - Calculating the absolute value of the difference between the detected water temperature and the first temperature (T 1); - Setting the second temperature (T 2), if the absolute value of the difference is less than or equal to the minimum temperature difference; - Detecting the time during which the second temperature is set; - Setting the first temperature (T 1), if the absolute value of the difference is greater than the minimum temperature difference or if the total time during which the second temperature (T 2) is set is greater than the lowering time. - Providing the water circulation system, comprising: - at least one feed line, - at least one return line, - at least one strand which connects the feed line to the return line, - at least one temperature control unit, which connects the feed line to the return line, whereby water can circulate in a flow direction from the at least one feed line, via the at least one strand and the at least one return line back to the feed line, - at least one consumer, which is arranged along the at least one strand and with which water can be removed from the circulation system, - at least one valve with which the flow rate of the water in the circulation system can be changed, - at least one temperature sensor (60,61,62), with which the water temperature in a line section can be detected, - at least one system controller with which the data of the at least one temperature sensor (60,61,62) can be processed and with which the at least one valve can be actuated; - at least one feed line, - at least one return line, - at least one strand which connects the feed line to the return line, - at least one temperature control unit, which connects the feed line to the return line, whereby water can circulate in a flow direction from the at least one feed line, via the at least one strand and the at least one return line back to the feed line, - at least one consumer, which is arranged along the at least one strand and with which water can be removed from the circulation system, - at least one valve with which the flow rate of the water in the circulation system can be changed, - at least one temperature sensor (60,61,62), with which the water temperature in a line section can be detected, - at least one system controller with which the data of the at least one temperature sensor (60,61,62) can be processed and with which the at least one valve can be actuated; - Determining a first temperature (T 1); - Determining a second temperature (T 2); - Determining a lowering time; - Detecting the water temperature with the at least one temperature sensor (60,61,62); - Setting the first temperature (T 1) in the pipe section by setting a first flow rate (D 1) with the at least one valve; - Setting the second temperature (T 2) in the line section by setting a second flow rate (D 2) with the at least one valve during the lowering time; - Setting a time window; - Setting a minimum temperature difference; - Calculating the absolute value of the difference between the detected water temperature and the first temperature (T 1); - Setting the second temperature (T 2), if the absolute value of the difference is less than or equal to the minimum temperature difference; - Detecting the time during which the second temperature is set; - Setting the first temperature (T 1), if the absolute value of the difference is greater than the minimum temperature difference or if the total time during which the second temperature (T 2) is set is greater than the lowering time. if the absolute value of the difference is greater than the minimum temperature difference or if the total time during which the second temperature (T 2) is set is greater than the lowering time.