The present invention describes a water distribution system 1 comprising a water supply, a heating source 100, at least one temperature sensor, a flow path for water with a user outflow UO, and a control unit for operation of the water distribution system 1, said temperature sensor being connected to the control unit, wherein the control unit also is connected to at least one presence sensor PS arranged for the detection of presence of a human or animal body in physical proximity to the user outflow UO and/or in an outflow direction area from the user outflow UO and wherein the control unit is arranged to drive a hot water pasteurization procedure of at least a portion of the flow path and out from the user outflow UO based on a response or an indication of no presence of a human or animal body in physical proximity to the user outflow UO and/or in an outflow direction area from the user outflow UO.