A method and a fluid tap device for retaining the temperature of a liquid, in a liquid distribution system having at least one liquid conduit extending from a liquid source to a liquid tap. After completion of a tapping operation and replacing the liquid with gas in the conduit, the refilling of liquid in the conduit is performed in three steps: a first step, initiated by activating the tap thereby causing a change of a physical variable which propagates backwards along the conduit and initiates a second step, the second step involving refilling the conduit with liquid from the source, while permitting remaining gas to escape via a gas passage separate from a liquid passage in the tap, and a third step, initiated when the liquid reaches the tap, involving opening the passage and permitting the liquid to flow out via the passage and through the tap.