The fluff filters are soiled.
Clean the fluff filters as follows:
Open the door.
Pull the upper fluff filter forwards to remove it.
Remove the fluff (see arrows).
Remove the fluff from the surface of all the fluff filters and the perforated laundry deflector.
Turn the yellow rotary control on the lower fluff filter in the direction of the arrow (until you hear it click).
Hold the rotary control and pull the fluff filter forwards to remove it.
Use a vacuum cleaner with a long crevice nozzle attached to remove any visible fluff from the upper air flow openings.
Clean all fluff filters with water:
Wipe the smooth plastic surfaces of the fluff filters with a damp cloth to clean them.
Rinse the filter surfaces through under warm running water.
Shake the fluff filters thoroughly and then dry them carefully.
Push the lower fluff filter in completely and lock it with the yellow rotary control.
Push the upper fluff filter all the way in.
Close the door.