Hi Richard
I have the same problem with my Miele T230C.
I am planning to take the top and back off and vacuum clean all the expected fluff off the insides. A new thermostat may be needed - cost around £15.00 from the internet. If a new heating element is needed the cost can be £185.00 or over £200.00 depending on where you source on the internet!
Peter Morris petermorriscpa@gmail.com
Peter Morris, November 2007