You are looking for a device similar to this one in the photo , you can reset it by pressing the red button in the middle , these are located in the burner areas and you may have more than one. let me know,
Thank you for your help but there appears to be no visible reset switch on this furnace anywhere. I think it might be in the blower area because there are two wires running to that area apparently for no other reason than to make it inaccessable without taking the furnace apart. The last technician did say if he had to come out again he would just cut an access panel in the furnace so he wouldn't have to take the whole furnace apart again although I don't recall the tech before him having to take the furnace apart. The blower is inaccessable unless you do. I just wanted to try to reset this switch myself because the last tech charged me $237 to do it.
If its a downfow furnace there will be an overheat switch on the blower housing,