A valve including a body delimiting an inlet duct opening into a first and second outlet duct. The body includes a first butterfly valve element and a second butterfly valve element. The first butterfly valve element is mounted on a first transmission gearwheel connected to a drive motor and is movable into two closed positions on either side of an open position of the first duct. The first transmission gearwheel is connected to a second transmission gearwheel, on which the second butterfly valve element is connected by a one-way positive drive element. When the first butterfly valve element is moved from an open position to one of the two closed positions in the first duct, the second butterfly valve element is driven from a closed position to an open position of the second duct. The valve includes a member for returning the second butterfly valve element to the closed position.