Before revision: Gravity-fed system Where a space-heating water boiler is employed, the traditional arrangement in the UK is to use boiler-heated (primary) water to heat potable (secondary) water contained in a cylindrical vessel (usually made of copper)—which is supplied from a cold water storage vessel or container, usually in the roof space of the building.
After revision: and IrelandGravity-fed system Where a space-heating water boiler is employed, the traditional arrangement in the UK is to use boiler-heated (primary) water to heat potable (secondary) water contained in a cylindrical vessel (usually made of copper)—which is supplied from a cold water storage vessel or container, usually in the roof space of the building.