I've just opened mine up - it's under the back panel - it's the bit that 'bulges out' - approx 8 screws.
Inside you will see some heating elements with two disk-like sensors screwed onto the element chassis.
It doesn't look like they are repairable (one of mine is faulty - it's permanently open circuit) so I'm off to do some research to find a replacement.
Not a good idea to bypass it!
Hope this helps.
Huw D.
August 2008