How can I repair faulty electric oven - Creda Europa model no. 43945?

The fan oven works up to temperatures below 200degs. Above this temp oven works but when door is opened with oven running, oven and fan stop as it should, but when door closed oven does not restart. After oven has cooled down oven will restart and work as normal below 200degs.
Have taken oven out of cabinet apart from the r/h terminal of the element showing signs of over-heating there appears to be nothing amiss. This is a 1980 model and has minimal wiring - two wires to the fan and two to the element from control panel. There does not appear to be any cutout sensor. Any solution to keep this excellent oven going. Thanks Simon