The invention relates to an arrangement (1) including two burners (10), which has a common exhaust gas guiding device (2) and a common supply device (3) for combustion air. A backflow barrier (4) blocks a flow of a gaseous medium in a flow direction and is arranged in the exhaust gas guiding device (2) or in the supply device (3). The backflow barrier (4) has an opening (40) and a movable element (41) which is movable between two positions. The opening (40) is open in case the movable element (41) is in one of the two positions and closed in case the movable element (41) is in another of the two positions.