Superb heater matrix replacement price? only blowing cold ai

[Andymac]

I'm going with a mate to check out a superb he is looking at buying, it's an 03 plate tdi with 97k with about a month mot for a GRAND! Wish I had the cash lol..... anyway, the seller has told him that the blowers only blow cold and after a look on google it looks like either a flap is stuck or the heater matrix has had it? I'm gonna take my lead and laptop to plug it in but if it is the matrix how much would it cost to fix at a garage? I don't wanna attempt it cos I don't get much time and I doubt he will want to either so need to know if the cost of a matrix renewal outweighs the low price of the car?

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