Replacing the fleece grease filter: . During normal operation (daily 1 to 2 hours) the fleece grease filter must be replaced every 8 to 10 weeks. Replace printed fleece grease filters at the latest when the coloured print dissolves. . Use only original filters. These comply with the safety regulations and ensure optimum function. Disposal of the old fleece grease filter: . Fleece grease filters do not contain any harmful substances. They can be disposed of as bio-degradable waste. Filters and ma