The two heating thermostats plug into the back of the drum, one is a hot one, one is a cold one, they need to be prised of the drum with a flat bladed knife,it's the hot one you need if this is the problem.when replacing make sure if they come with a washer, in any event they need to be replaced with waterproof glue, a special type of glue you can get when you buy the thermostat. Before you do that, take your heating element out, and check it hasn't snapped along the length of heating wire, also check it is not touching the casing, if it is broken it will need replacing and you may not need to replace the thermostat, the heating element comes in a complete unit including the casing.
John atkinson
July 2010