OK , here is the weirdness of the day! 2001 Amana GFA furnace. Turn thermostat on, furnace kicks on, flame looks great , blower is quiet, everything seems to be working fine. So I walk around to check air flow from the vents and guess what? Heated air is coming from the cold air returns and the floor registers are sucking air back to the furnace ! These people have been living in this house for 9 years with the furnace working backwards!
Question: What would cause this?(I know it’s not my job as an Inspector to determine cause, I just would like to know). Could the blower be wired wrong and running in reverse? This is the first time I’ve come across something like this.