Was doing a job yesterday and happened to notice that the cold water storage tank was also used as the F&E tank. The cold fill had been connected about halfway up the tank and the vent over the top as normal but the top of this and the top of the hot water vent only went about 150mm above the cold water storage tank before bending back down. I would not thought this was legal as contaminated water from the central heating system would get drawn in to the cold water tank, although not drinking water it is still classified as potable water.