Combine harvester with system and method for removing accumulated material from a feederhouse

A combine harvester comprising:

• a feederhouse mounted to a chassis and adapted at a front end to support a crop gathering header in a manner that places a front inlet in communication with a discharge opening of the header, the feederhouse defining a crop conveying passage and housing a conveyor;
• a duct mounted on the feederhouse and defining a channel that is in communication with the crop conveying passage via a first opening wherein the first opening has an associated first closure element that is movable between an open position and a closed position;
• a fan arranged to move air through the duct, the fan being operable in a first direction to create a suction airflow to extract dust from the crop conveying passage and discharge the dust through the duct,
• wherein the duct comprises a second opening having an associated second closure element that is movable between an open position and a closed position,
• wherein the fan is selectively operable in a second direction to create a blowing airflow to open the second closure element and vent air through the second opening.