The outside temp in Massachusetts has been brutal lately with the heat index looking to be in the 100's for the next few days. I have mine on Auto with the temperature turned all the way down to LOW. It's blowing, but the temp isn't really cold. I took it off of auto and the temp went down and there was ice coming out of those vents! Is there any reason for the temperature difference? possibly a blend door not working? Anybody have any thoughts?