magic chef oven overheats

As I was cooking the Christmas Turkey today the oven was set at 350°, the temperature got as hot as 500°. I thought someone had accidental turn it to broil, but they didn’t.

This happened all day. Set it to 350° and the temperature would rise again.

This range is over 25 years old. Any ideals on why this is happening.

This is an electric drop in range.

Thanks

John

I cannot find any info on this unit.

If it uses a mechanical thermostat then that is probably toast, either the contacts are welded together or are sticking closed.

If it has an electronic timer then perhaps it is the sensor/probe. See the following on how to check it.
http://www.applianceaid.com/elecrange.html
See Items 7, 8, 20 and 21.

Also it cold be the relay contacts on the control board.