Good evening, I have recently bought an Audi A6 (Year 2007). I'm experiencing an issue  where hot air is coming from the vent near the bottom of the front windows and the side vents only. Although the middle vents are blowing cold air. I have tried setting the heating to different levels but that didn't make any difference. It might be a user error as this my first Audi. Any idea why this happen please?

If cold and hot air is blowing then there could be an issue with the control unit. Yu could get a diagnostic check carried out to see if any fault codes flag up. Did you buy from a dealer? If so , abd within 30 days of purchase I'd take it back to them to look at as you have 30 days to return the vehicle for a full refund.