Most installers today have heard about unvented hot water systems as they been present on the UK market for some time now. In fact the technology is used exclusively in most developed countries around the world exception of the UK. House Builders have recognised this and the majority of new houses built in the UK are designed with unvented hot water systems. However not all plumbing professionals are familiar with how the system works so therefore we would like to offer the information below as an introduction. And if you already know something there may be something of interest.