This evening we had the oven going at 450 F, opened the door half way through baking to flip stuff and then consecutively turned on the broiler, again opened the door to flip stuff. After we sat down for dinner, the F9 code came on and the oven started to beep. It could be stopped but then would resume a few minutes it later. The oven had done this to me once before last year just after we had it installed. I am assuming that when the oven is hot and one opens the door to fiddle faddle around with the food the controls get over heated and on comes the error code. The owner's manual writes about the error could had how to reset the oven by cutting the power source, but does not indicate exactly why it happens. Has anyone else had this trouble and/or could anyone tell me for sure, why it happens?

Thanks

Maria