Can someone please explain to me why I don't feel any heat coming out of the foot wells when I have the heat on. I tried all of the buttons and still no heat out of those foot wells. I get plenty of heat to come from the side vents (none comes from the center vents either). I've tried economy (I believe that's what the symbol stands for), I've tried both of the other buttons but still no heat from the foot wells. I know that this subject has been discussed plenty of times before but when I try to do a search I still can't find anything.