Hi All,

 

New to this forum,

 

I have a Audi Q3 2014 2L 8U, petrol with a dual temp control and the heater does not blow hot air. I have read a few forums but the feedback has been inconclusive.

The Air Con (cold air) works fine but it is the warm air that does not work, Its winter here in AU now and this is a show stopper. Hot air comes out of the vents for the first few seconds and then the air cools down. I borrowed a OBDEleven from a friend and the diagnostics shows no errors under Air Conditioning, I don't have a VCDS,

I can turn in the heater on, set my temperature on either side (passenger or drivers) to HI or anything down to LO, and the fan speed works depending on the level I set. Vent selection also works fine and so does the cabin temp sensor.

The engine temperature is also fine, within a few minutes it reaches 90 degrees and maintains. Read it could be the matrix (radiator inside the cabin) so removed the glovebox and passengers side panels where I can see 2 aluminum pipes connected to the matrix. One pipe is extremely hot (lower) which I assume is the supply and the second pipe (upper)  is hot which I assume is the return. When I feel the side of the matrix, the top end is very hot but as I run down my hand on the side of the matrix the temperature drops drastically so 1/3 down the matrix is cold. Can the radiator block just under the inlet as the return pipe is very hot ?  Has any one experienced similar and did you attempt to replace the matrix on your own ?

 

Any help or suggestions will be greatly appreciated,

 

Theo

 

 

It could be a sensor issue in the heater control. My advice would be to get a garage take a look. 

Hi from the excellent photo supplied it may be that the matrix is partially blocked as it looks as though only a small portion of it is being used hence the bypass effect. Looking at the writing on the side its made by the French which would explain a lot, never done one myself but it looks good for access if you are handy with a socket set.

Steve.