Drivers side heater blowing warm only

[noshock65]

Good afternoon,

A6 saloon V6 3.0L TDI 2012

My A6 will only blow warm on drivers side (passenger side works normal) from all vents. The dial is not digital and will turn down to cold but on maximum 24 it is actually only about 10 degrees. This started suddenly and my local reliable garage have tested the heating system and have said there is no faults showing and suggested something may be blocking a vent which would mean removing all the dash with considerable labour charge just to expose/diagnose.
I'd appreciate and advice/help please.

Thanks
Steve.

[Crasher]

Could you private message me the reg or post the VIN?

[Crasher]

Get the HVAC system scanned for fault codes, the air blend flap servo motors are prone to failure plus ask the person doing the read to look at the air outlet temperature sensor values to make sure they make sense. If nothing shows up then you are looking at a partially blocked heater matrix.

[noshock65]

Thanks Crasher
I’ll get them to check faults you’ve suggested. If the matrix is partially blocked what’s the best treatment for that ?

cheers Steve

[Crasher]

Replacement which is a total nightmare, back flushing rarely works on modern heater matrix's.