heater problem
 

hi guys I have a bmw 318ci e46 with climate control. I noticed today that It is blowing out hot air and is not responding to wat i am asking for on the unit even when i turn ac on the engine fan turns on and car idles faster but stil blows out hot air. could this be the heater thermonstat or blower resister? I put anti freeze in car today but very much doubt that has anything todo with it.

has no one heard of this problem please say if you have

took it in to bmw and hav found the problem so I will buy the part this week so I can fit it in my spare time