A4 heater, only blowing cool air

[Usman-tgeh9]

Tonsko said:

The matrix has been flushed, coolant seems to be moving ok.

Drive it a bit more now (it's the other half's car mostly) and if you have it on low power (i.e. one or two bars) then you get warmth. Any more blow and it starts cooling down - presume because there's not enough heat exchanging going on.

Does this suggest that the matrix is buggered? I'm told it's a , as the dash has to come out

Hi Tonsko,
How did you fix the issue with low power (2 bars) hot air comes out but when you put it higher then you get cold air?

[wilko4767]

I have an 2001 Audi A4 the heater blows cold only. When looking in the engine bay the pipes the are next to the battery one is hot when running but the top is cold. I have taken the top hose off and the pipe is dry. Any advice on this guys?