Hi Gareth, can travel over a month to from work (12 mile return) use no water, new cap fitted, had both water system pressurized and head tested, both ok, car runs at proper temp, no overheating, no water deposits on dipstick or oil cap. As i said only uses water on 1hr+ journeys, also after half hour running engine near side blows cold air, off side blows hot air, checked footwells for water from heater matrix and nothing snuff dry. Its puzzling