Hi Richard,
Mine too displayed the same problem - not heating, therefore not cleaning or drying properly (door still cold 20 minutes into cycle). I've found that there is a common (yet not often talked about) issue with a point on the controllers circuit board. If you remove the controller (simple to get at), remove the circuit board from the controller and flip it over you will see a 'burnt' solder joint on one of the legs to a black box component - resolder that joint and all should be well. Don't pause or open the door during a cycle as this seems to cause the joint to blow.
Cheers,
Solly
Solly, May 2008