Hi, I did look at the thermostat when trying to find out why my wd12 washer dryer wasn't working. If you short the terminals together, you get the same effect i.e. the prgramme knob rotates non-stop. So it probably is the thermostat, which is located on the top of the dryer casing - immediately visible when you remove the washing machine's top cover. If you e-mail: Appliancespares2go [sales@appliancespares2go.co.uk], they will send you a diagram and part number - they seem very helpful.
Regards
Andrew
Andrew Green, August 2006