Heating and/or air-conditioning device for a motor vehicle with removable air filter

A heating and/or air-conditioning device for a motor vehicle which includes a bulkhead separating the engine compartment from the passenger compartment, the device comprising a casing housing a motor-driven fan unit suitable for impelling a flow of air, a heat exchanger and a removable air filter suitable for filtering the impelled airflow, wherein at least a part of a wall of the casing is arranged adjacent to the bulkhead, and wherein the bulkhead and the casing include respective access apertures arranged facing one another in order to allow the filter to be withdrawn from the casing via the engine compartment, exchanged if appropriate and re-inserted into the casing, and further comprising a cover plate suitable for closing off both the aperture in the bulkhead and the aperture in the casing wherein the cover plate includes a flap suitable for closing off the aperture in the bulkhead, on the engine compartment side, and a stopper attached to the flap and suitable for jointly closing off the aperture in the bulkhead and the aperture in the casing and wherein the stopper is formed from at least one insulating foam.