As the name implies Unvented Cylinder Systems have no vent pipes, and so when heating water have to provide room for its expansion. This can be accomplished either by accommodating it in an external expansion vessel or, in the case of bubble-top units, an internal air bubble within the unit which is generated when the system is commissioned.
In this section Venteuro have a large selection of discount external expansion vessels in a huge selection of sizes and from all the major manufacturers such as Zilmet, Flamco, Reliance Water, Vaillant and Varem, all designed to contain the expanding heated water in a hot water system, which can be sited either directly on a unit or, if required, remotely sited with the inlet control group. These units are manufactured from copper, glass-lined steel or stainless steel.
We also have expansion vessels available for combi storage units. This type of system incorporates the benefits, features and controls associated with unvented systems but has a smaller tank and therefore more limited storage capacity for hot water.