Audi A5 - A/C blowing cold air on heat setting

[dringala]

My 2017 A5 has started to blow cold air on the driver side when setting the temperature warm. It blowing hot air on the passenger side and rear.

 

Any one experienced this before or have any suggestions? 

[Steve Q]

I'd recommend a diagnostic check to see if any fault codes flag up. 

Does the engine get up to temperature and stay there? 

If not then the thermostat could be faulty. 

In failing that it could be an issue with the heater matrix and heater control unit.