If your tumble dryer displays error code F66, it is probably due to insufficient ventilation.
Sufficient air for ventilation: To ensure sufficient ventilation for the tumble dryer, it is important that there is sufficient space around the appliance and that the surrounding space is generally well ventilated.
Damaged lint filter: Error code F66 can also occur due to a clogged or damaged lint filter, which can result in poorer ventilation. Therefore, clean the fluff filter regularly or replace it if necessary.
Dirty condenser filter: Also clean the filter in front of the condenser. The condenser filter tends to wear out over time. If it is worn or damaged, it should be replaced.
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