LOL, I'm a f'n moron. My middle vents weren't putting out heat last night but the winsheild and floor worked fine. I was like 'fcukin wtf'... I feel pretty dumb.You probably need to change the setting on the dial in the middle of the two main vents. It is probably set to 3 blue dots. You need to set that to 3 red dots and you will get heat. I bet thats what it is.