I have the same problem. I think it was caused by the venting hose being trapped after moving it to decorate. As an ex-TV engineer, I thought it likely to be some sort of thermal fuse and took it apart to look but there are 2 devices (resistors? diodes?) in series with the heater element which I cannot identify and do not know where to obtain replacements. As the dryer is 10 years old, I am reluctant to pay £160 for the heater complete.
Bob, February 2012
Heating element, heater thermostat, control unit, take your pick, in that order, needs them tested.