i fell asleep and i accidentally left my oven on for 3 hours ?

There is something wrong with leaving food in the oven on 'High' for 3 hours.

Yes you could have started a fire!!!

you burnt your food, thats all.

People leave their ovens on for hours when making large turkeys or slow roasted pork for pulled pork.

The ONLY reason there could be a fire is if there were flammable items laying on the stove or your food inside the oven set itself on fire.

The suggestion made to set a timer is a good one,especially if its late and you know you're tired.I have to confess that the same thing has happened to me a couple of times over the years.It was a disaster,needless to say.Also,another good post asked about smoke detectors. What about that ? I strongly suggest that you tend to that asap. btw,you fell asleep,that's the point to take away.Not much chance there's a problem with the oven.

What happened to your smoke detectors? Why aren't they working?

First the items you left in the oven for that length of time and at that temperature were small things and would burn even if you left them for an hour.

I have cooked lots of things in my oven for far longer than that and have not burned anything. A bread in the Dutch Oven at 475 for almost an hour. A Deep Dish Pizza at about the same temp for an hour.

The oven is fine. I have slow roasted items for 8 to 12 hours so it is not the fact that the oven was on for that length of time. The problem was the size of the item and the length of time you cooked it.

Next time you put something in the oven set a timer. If you fall asleep at least the timer will wake you up.

It could have started a fire but since it didn't, you'll be okay. Clean the oven before using it again. For the next batch of.chicken bites, use the mocrowave. That will turn itself off after the cooking time.

Nothing wrong with the oven. You just left food in there until it got burned. How dumb are you that you cant figure out why your oven was smoking after leaving food in it for that long?

"could it started a fire"  Yes, because food is flammable.  Food catching fire in the oven would consume the available oxygen fairly quickly, although a flare could continue to burn at the vent (usually located under a burner).  When the oven door is opened without letting the oven cool, there is a significant risk of flashover (ignition of explosive gases) producing a brief, but very dangerous, fireball blasting from the oven.

Is something wrong with your oven because it burned food that you left in there at a high temp for 3 hours? No.