I have a TRANE heat pump that is about 3 years old, the ductwork was all replaced/installed at the same time as the heat pump. Recently, I noticed that one of the vents is blowing cold air. The vent in the next room, less than 2 feet away, blows nice and hot. Why would this be?
The air handler is underneath the house along with all the ducts and the returns in both rooms are below insulated windows.