water problems!!!?

hi all i have a few problems with a clio rxe 1998 1.6. to start with i was checking my washer fluid and also realised the water tank was below min (normally i check this frequently lol!!) so i topped it up 2 the max line with anti freeze and water over the next few days its been drinking water but theres no signs of a leak on the water system and it does not overheat???!!! just operates at normal temp any clues to wot this could be???? thanks j