Belling format cooker main oven not working?

Hi, hopefully someone can advise me how to fix this!

The main oven isn't heating up but the oven lamp is on and the fan is working. The top oven works as noraml. I have tried turning it off at the mains, making sure that it's not on auto, etc but nothing seem to work. It has been on for nearly half an hour now and still not heating up.