Mike Gibbons wrote in
:

4. Proposed course of action: replace the overtemperature cut-out
and go round all the connections I can see to make sure they are
secure.

How does that sound? Any other ideas?


Good analytical method :-)

By all means change the overtemp cutout but I think it an unlikely failure
mode.

More likely I think would be an air leak from the inside of the oven to the
case. With the oven set high that will leak high temperature air into the
case cavity and cause the overhea to trip.

Try an internal visual inspection or feel around for hotspots as the oven
heats up.