Indirect copper hot water cylinders are designed to work in conjunction with central heating systems. Heat is transferred from the boiler to the water contained in the cylinder via a heating coil.
Vented hot water cylinders are available in different grades – 1, 2, and 3. The grade determines the thickness of material required to make the cylinder, this then determines the amount of pressure the cylinder can withstand.
They are usually size on a “working head” in meters which means the height difference between the cylinder and the header tank usually in the loft.