The temperature of the hot water pipe network is temporarily increased for thermal disinfection. The aim of this short-term temperature rise is to increase the death kinetics of the CFU (colony-forming units) in the warm water system. If the temperature in the warm water network is increased from 60°C to 75°C, the volume flow also increases. The circulation pump must be able to provide this additional volume flow. The necessary duty point of the pump and the temperatures in all rinsed warm water run sections are calculated. A warning message is displayed if the temperature in the flow path drops by more than 5°K.