17The main ovenHeat zonesThere are zones of heat within the oven. Thetemperature in the middle is the gas mark youhave chosen. The top of the oven is slightlyhotter and the lower shelf slightly cooler. Thebase of the oven is quite a lot cooler. You canmake use of these heat zones when you arecooking foods requiring different temperaturesall at the same time.If you are cooking more than one tray of similaritems, for example cakes or biscuits, swap thetrays during cooking or you can remove the toptray when the food is cooked and move thelower tray to the higher shelf to finish cooking.PreheatingWhen you need to preheat the oven, werecommend you do so for 20 minutes.For recipes needing high temperatures, e.g.bread, pastries, scones, soufflés etc., bestresults are achieved if the oven is preheatedfirst. For best results when cooking frozen orcooked chilled ready meals always preheat theoven first.To fit the main oven shelvesThe shelf should be fitted with the straight rodsuppermost on the frame and the forms towardsthe back of the oven.To remove a shelf slide the shelf towards youuntil the shelf stop is reached. Tilt shelf up atthe front so that the stops clear the sidesupports. Lift shelf clear.To install a shelf, reverse the above steps.Using the main ovenFully open the door before lighting the main oven.Push in the controlknob and turn it to gasmark 9.When the burner haslit release thecontrol knob.There will only besmall flames at first.When the burner isshowing large flames,adjust the setting asrequired. Do not close the dooruntil the burner isshowing large flames.