hi paul , probaly early signs of fridge problem , what happens if temp in fridge goes faulty one of the first things to happen is the water bottle situated behind the bottom salad drawers start to freeze which stops the water getting up to water dispensor ..
what to do 
1st  make sure you dont have temp set to low in fridge ie if its set at 1 this can freeze bottle ..
2 if set ok ie 3-4 , to check if water is frozen inside bottle - simply use a hairdryer on bottle , gently heat bottle for about 10 minutes ..
if water then starts to work - you then know its defo frozen water causing problem..
if you do have frozen water its more than likley the start of further trouble , check the panel that bottle is screwed to for ice etc .. especialy at the vents ..
heating the bottle will make water work for a week or so but if it re-freezes you will need a repair kit 
call /txt  for advice / spares etc ... 
07407 734 204 
we supply over night spares at very good prices 
thanks
                
 ally
                
 February 2012