Customer Questions and Answers for Microwave Charcoal Filter by Bosch

This is a charcoal filter used in over-the-range microwaves to remove smoke, odors, and grease from the air when the unit is set to recirculate rather than vent outside. The filter sits behind the vent grille and traps airborne particles as air passes through. Replace it if you notice lingering cooking odors, reduced airflow from the vent, or visible grease buildup on the filter - typically every 6 to 12 months depending on cooking frequency.