Where might I find this flame sensor? I have a carrier unit.

Did you break it or does it just need cleaned?

I don't think I've broken anything. It just quit working.

If you have a flame sensor it will be located on the left side area of the furnace. It will be a wire looking apparatus on a ceramic base, it will stich up in the flame of the burner on the far left side. With a flash light you should be able to see it very easily