My CDA 9002 dual oven dual fuel range cooker’s main oven is not heating up properly. I have replaced the oven/grill top element but it has not solved the problem. The only other thing I can think it could be is the thermostat. I have had a look but cannot see anyway to get access to check it out. I have the back cover off ok but either need to get the side panel off or front panel. Anyone know how to access the thermostat ?