Device for heating-ventilating and/or air conditioning comprising a damper door for controlling an airflow, arranged in a housing

The device has an air feed valve (16) housed in a box (10) and including a body (18) integrated to a rotating shaft (20). The box provides two opposite walls placed across the shaft. The valve is provided with an elastic strip (30) that provides support against a contact zone of one wall. The flap pushes the body of the valve in a direction opposite to a force exerted by the elastic strip on the contact zone.