Water Loss....

Having a bit of trouble at the moment, my car seems to be loosing water from the coolong system, First off it took a week to set the sensor off then more recently about 3 days!! I have recently had the cambelt done at which point they changed the water pump. Although the gaarge that did the work have checked the car out they say there is no evidence of a leak at the pump.

So far they have checked the car out, changed the resevoir cap (There appeard to be residue from a leak down the side of the bottle) and said if its not that then its the head gasket!?! Anyway having now changed jobs (this week) I no longer go near the garage that done the work so if it is the pump will it still be under the parts guarentee if someone else does the work? (From what I gather its an awkward job which is why they do it with the cambelt)

Just thought I'd check on here to see if anyone had any ideas?

The works were carried out by an independant.

Thanks

Tom