Your heater switch can be off, but if your wheel is on the red and not the blue, it will throw heat. And make sure your to temperature knobs are turned all the way to the blue, under 22c(or whatever). If it's over on the red side over 28c(or whatever) it will throw heat even if your fan is off.
1994 318is-Sold July 13th 2010.. Sad Sad Day