the reason I ask is because it seems the heating system is working fine as the windscreen / feet get hot. it seems that its the direction of the airflow that is the problem. Silly suggestion... right in the middle of the dash there is a temperature selection blower specifically for the middle / side vents have you turned that to hot? Shown here in my crude 2 second photoshop as TEMP Set 2 you need to turn this so that its showing 3 red dots on the dial other than that It could be some blocked vents..... Could be the selector button is broken...... Could be the selector valve doesn't turn enough to blow air into the centre vents... will have to have the dash off to see Let us know how you get on