Not a clue, havent had to have mine done yet either, but the subject does make me wonder when it is due (certainly before the summer hols) but I bet you can safely assume that it will the the normal cost of servicing (plus parts as necessary) and maybe an extra "fee" on top for travelling out to see you - and i guess, unless he has to travel to 3 different sites, then he could only charge you one "callout fee" if not - be cheeky and haggle! heheh