Filter at bottom of machine needs pulling out and cleaned on a regular basis. This is a common fault and the lights is telling you to clean the filter. It is a large filter that unclips at the bottom front of machine. Remove two small screws from the front of the filter located left and right and gently remove the front plate. Once removed you will see a metal filter clogged with clothing debris. Clean with cotton buds and a damp cloth till clean. replace all parts and you should have it working once again with a good heat source as well. Every 2-3 months is sufficient to keep it cleaned. Hope this helps.