Thanks for replying Jhf. There's no thermostat, the oven has a PTC sensor. I can't find how to test that at the moment. It's showing a resistance / continuity of 543.5Ohm.
I tried all the oven programs, grill, base heat, fan heat etc and nothing started heating. Only the light came on and the rear fan got going.
I've resistance tested all the elements and they're all fine.
There does seem to be some other parts, perhaps thermal cutout etc but I can't find description of them or what their readings should be!