Tested? Two people have told me my Goodman GMT115-5 Furnace is too oversized for my condo. They say my air ducts are two small. I do have a two floor condo. I have 3 bedrooms (3 vents). Kitchen 1 vent. 1/2 bathroom (1 vent). Full bathroom (1 vent). Living room and dining room is open together and it has two vents. Finished basement has 2 vents and laundry room has one vent. However, when I have the gas line open fully the system overheats and blinks 4 times and that referes to open limit switch. Now, when I turn it down a notch. It does not overheat and the burners keep running. So I don't remember if I have played with this limit switch in the past or someone else may have. But, is it set to right? Should it be pushed down to Auto? Or should I set it to something else?