Step 1
Stand directly in front of the furnace - looking straight at the front. There will be two large panels - one with vents and one without.
Step 2
Open the vented front panel on the cabinet of the furnace. If there is not an obvious handle, reach to the bottom of the panel and feel for a finger sized groove. Lift straight up until you feel the panel release and then pull the panel toward you.
Step 3
Locate the model and serial number label inside the cabinet of the furnace. The model number will be four letters, a dash, and then six more characters while the serial number is ten characters long.