So was it the heater matrix mate? I'm in exactly the same boat as you. Got a coolant leak sorted but since then the blowers have been totally shite. They just dont get hot anymore.I’ve emailed Seat customer service with the hope they might be interested in reimbursing some costs. I’ve had other expensive repair bills in past few months and the car has only done 36000 miles.
Its off to a seat dealer now anyway hopefully they are able to identify and fix the problem. It’s had a new stat and a new matrix so I’m not sure that there can be much more in the way of unexpected cost. (Note issue present before stat change).
in future it’s going to VAG specialists only..