A method for disinfecting a water system of an aircraft includes the introduction of damp hot air at an inlet of the water system by a ground service unit； flushing of the damp hot air from the inlet through water pipes of the water system to an outlet of the water system； and extraction of the damp hot air at the outlet； wherein the damp hot air is flushed into the inlet and out of the outlet over a predefined disinfection period, and wherein the damp hot air has a temperature between 60° C. and 80° C.
