A dryer having a filter sensing system that warns a user that a filter requires servicing is provided. The dryer includes a drum that retains laundry. Hot air is drawn through the drum (for drying) and out an exhaust casing having a filter for removing lint and other particles. The temperature difference of the air in front of the filter (on the drum side) and behind the filter is determined using temperature sensors. When that temperature difference exceeds a predetermined threshold, a control unit causes a notice unit to produce a warning signal that informs a user that filter service is required.