2014 s3 heaters blowing cold

[Paulglasper]

Hi guys.
I recently purchased an s3 8v 2014. I absolutely love the thing.....until..... leaving work today was the first time I’ve had to use the heaters since owning and in the 12 mile journey home from work my heaters never got warm. Climate control in auto with AC off. I turned the CC system off for a minute then turned back on and had hot air very briefly but this quickly cooled down. I’ve read about heater matrix’s being blocked and the £££££££££ that Audi want to replace.
Anyone have any advice on stuff to try before I take it to a garage or dealer?

 

[Bigjase88]

Most likely blocked heater matrix as the crappy silica bag will of burst.

new matrix required

 

[CanadaA3wales]

Just grab the silica bag from the water res and see if its split, if it is you are looking at a best part of £1000.00.
You may get away with a flush and clean, but not likely.

What ever you do, dont take it to audi as that £1000.00 will turn to £3500.00, get a good German Indy to look at it.

First thing I did was remove the bag when I got my car, dont see the point of it being there.

 

[mikeking745]

Most likely the shut off valve. Was on my and on a mates car.

 

[rvtb101]

Most likely the shut off valve. Was on my and on a mates car.

What is this shut off valve? big/expensive job?
TIA, Rich