urS6 - Heater - No Heat ? What's wrong?

[macspring]

As per title.

Have a 96 urS6 with "proper digital a/c", similar to a LHD RS2 a/c set up.

The car's system blows cold air when asked, but recently doesn't blow hot air when asked.

Can someone suggest what might be wrong ?

Thanks.

[Error404]

disfunctional flap motor?

[macspring]

Does such a fault show up if connected to vag-com ?

Are they hard / dear to replace ?

Is second hand a viable option ?

[s2_wot]

Is the coolant level a little bit above max? That was the only place I could get that to consistently deliver heat.

Also when the water pump was leaking air back into the circuit, the circuit was losing pressure and not pumping the coolant into the matrix in the cabin. Everything was perfect after the pump was changed.

The water bottle and cap are also new in case you feel the urge to change.

That module has a very good diagnostics setup, I had a thread about it before and urS4boy pointed me in the right direction.

HTH

[s2_wot]

have a look through this thread:

http://www.s2forum.com/forum/showthread.php?t=48730

[macspring]

Shane,

Will do, thanks.

[byd1380]

I had a 2.5 TDi Quattro and the heater was rubbish, scanned in VAGCOM, all clear, think there are some posts Audifans.net about heater issues. Generally it's the heater matrix that is rubbish, I bought one from GSF for about £27, but sold the car before fitting, cause it was supposed to be a pig of a job. My current S6 has a great heater :-)


Ivan

[prj]

I have had the same problem.

Let me describe some problems I had:
1. I never got any hot air into my feet... when disassembling it turns out the air guides were broken off by one of the caring previous owners.
2. My heater matrix was toast, that had to be replaced.
3. My climate fan was dying as well, had to have that replaced too.
4. Some flaps get stuck sometimes, pull fault codes with VAG-COM from the climate control unit, it will tell you if any flaps are stuck.

HTH

[macspring]

All,

Thanks for replies, I noticed a bit of fogging up on the front windscreen on certain cold mornings over I suppose the last three weeks.

Thinking / fearing the matrix may need to be changed, which I sure is worse than the S2 ABY a/c one I did in the summer.

As a matter of interest, if anyone has done both, which is worse to do, or are they both as "lovely" as each other ?

I presume the C4 is like the B4, in that Audi get a heater matrix and then build a car around the matrix.

Will rope in Mark for the codes pull and take it from there.

[s2_wot]

David,
will you humour me by checking something please...

engine up to temperature. Air con off (you know that snow flake thing on the display). Set the air to be delivered to the central vents in the dash manually and disable the others.
Max fan speed for the craic.

Then gradually increase the required temperature in 1 degree increments. I seem to remember only getting good heat when I asked for max temp. At the time I discarded my train of thought... but that would tend to suggest that one of the temp sensors was reading a false temperature.

AFAIK there's 2 matrix things in that system, one for hot and one for cold and the temperature is controlled by the operation of flaps that cover the matrix's.