I have exactly the same problem and not solved it yet. I have checked that the heater element seems ok witha multimeter (you get at this by taking the lid off the machine). I have tried running the dryer cycle and get zero volts at the heater element so Im assuminga thermal fuse may have blown. I opened up the fan casing and it was choked with fluff so suspect this is it.
See website: http://www.indesitparts4u.co.uk/index.php?_a=viewProd&productId=241
John, May 2009