How can I fix my Miele T7734?

Load tumble dryer(size of load doesn't appear to make any difference),select Normal/cotton setting ,turn on.
Within 4/5 mins the machine beeps and the red warning light "cleanout airways" flashes. I know I have already cleaned out all the airways I can get at so I turn the machine on again, same thing happens. After the 4th or 5th time of restarting the machine it keeps going and the clothes are perfectly dry. This has been happening for quite a while now and I am at a loss as to how a normal householder can clear out any more of the "airways" than I already have. What's going on because once I can get the machine to "carry on" its working perfectly well.