losing coolant

Hi, not had this superb that long and already a problem has arisen!

Twice now I've had the coolant alarm chime to tell me my coolant was and is low,  I topped up thinking it was just low at first but it chimed again using it up only covering 200 or so miles, my mechanic had a quick glance and said it looks like it could be the water pump, if it is then I'll get the timing belt all done at the same time as the car has now done 87k.

I've only just bought the car from a small motor company trading from an industrial estate and the car is an ex lease with printed history so it does seem like everything was done according to the book, just a bit unlucky I guess but I'll be calling the dealer up when he comes back from his holiday and I'll be expecting him to foot the bill as I've owned the car less then a month! 

Has anyone else had water pump issues?