A method for operating an on-board water supply and distribution system of an aircraft for supplying water includes a central water tank, central pump, having an upstream side and a downstream side for conveying and pressurizing water from the upstream side to the downstream side, consumer assemblies including a supply device and a buffer tank including a pressurizing device. A high-pressure conduit system connects the downstream side with the consumer assemblies and is configured where the central pump operating can deliver water from the downstream side to the buffer tank of each of the consumer assemblies. The method includes operating the central pump where water is pressurized to a first pressure, monitoring pressure in the high-pressure conduit system for a first period of time, and providing a first failure signal when pressure in the high-pressure conduit system drops below a second pressure within the first period of time.