I have the same problem on a Format 6060C oven. Most likely the element has burnt out. This will not always be a visible fault but if it is you will see a rupture on the element surface (use a mirror/lamp with power off as below and don't touch!). Only way to be sure is to measure the resistance of the element with a meter (POWER OFF at fuze box AND kitchen wall switch and test for zero volts before touching anything or you will kill yourself!). It will either be infinite resistance (blown) or zero if shorted case to core. If OK it will be 20 to 40 Ohms depending on wattage. Also confirm mains gets to the element itself (don't leave the multimeter on the resistance setting as I did and blow it up!) If you have a double oven then you can compare top element with bottom. Easy to replace element at £25. Wonderhowto.com has some good dismantling videos. Again, just be careful/methodical, repeatedly checking the power is off before touching. If you are inexperienced with electrical testing a cooker fault is not a good place to learn. Engineers will charge £125 or so to do this. I am just repeating what I have found across numerous websites so i hope it saves you some time. Good Luck to us both!
Mike Stevens, January 2010