GBP

Hi... I wonder if someone could really help me... the heating seems to have just stopped working inside my A4, details and changes below:

1. had Cam belt and water pump changed (at an independent) - all worked fine and i'm sure that heating was okay (this was mid-Sept)
2. Heating stopped working - Indie thought it could be the Thermostat, so had that changed, no improvement! - engine temp rises and stays at 90c
3. Radiator checked - flushed - no muck detected
4. Heater Matrix checked - flushed - no muck detected
5. checked that all flap/motors are working using VCDS, all fine.

I don't know what else to do, 1 garage thinks that the heater matrix had packed it, and another thinks that the new water pump may be faulty.

But, if it was a faulty water pump, wouldn't my engine have over heated by now? (i've driven at least 1k with cold heating!)

If it's the heater matrix, i've not experienced any leaks and the pipes do get fairly hot inside the car (i've removed the drivers side trim to expose the heater matrix)!

Back to the water pump, a garage attempted to test this - please see video linked - should there be a continuous stream of coolant when revving the car? (revved at 2000, 3000 then 4000)

Please help! I need heat in my car and the mornings have started to get colder!

thanks in advance guys!
GBP