Using smeg range cooker without timer??

I think this model is called the SUK92 and is the dual fuel stainless steel 90cm wide version.so the electric knocks off and cooker restores to factory settings.now can't figure out how to cook without using the timer.when I choose temp and select fan light and fan comes on but no heat.this is the big left hand oven.please help,really don't want to cook with timer.def used to be able to cook like this before electric went off