The invention relates to an assembly for a machine for preparing beverages by infusion of a liquid, that includes a holder (10), a boiler (20) for heating the liquid for producing beverages, assembling element (21 a,21 b, 25) provided so as to selectively allow the connection and removable disconnection of the boiler on the holder (10), a first fluid communication element connected to the boiler (20) and a second fluid communication element connected to a fluid inlet circuit and/or a fluid outlet circuit, the first and second fluid communication element being adapted to interact in order to provide fluid communication between the boiler and a fluid inlet circuit and/or fluid outlet circuit, characterized in that it is adapted so that the connection and the disconnection between the boiler (20) and the holder (10) respectively enables and disables the interaction between the first and second fluid communication element.