A bit late but a reminder. This should be in your manual if you have one.
One major cause could be failure to clean drum door filters, dry clean. On most, if not all, there is one also at bottom accessible behind drop down panel this allows cool air circulation which may be the cause. Read up how to clean, some with water / garden hose some with vacuum cleaner loosening the dried fluff with care as these fins/veins are easily damaged. Don't forget if it has a moisture tank top of machine empty it after each use.
BobUK, November 2019
