The first hot water cylinders were heated directly by kitchen ranges and similar devices and appeared around 1860. By the beginning of the twentieth century, these systems were becoming more affordable for the ‘middle classes' and the UK cylinder industry began to develop.

The Waterheater Manufacturers Association

Formed in 1913 as the Copper Cylinder & Boiler Manufacturers Association. Original members were copper hot water cylinders manufacturers mainly located in the north of the country. The copper cylinder industry reached its peak in the central heating boom of the late 60s and early 70s when hot water cylinders were most often indirectly heated by boilers. By the early 80s combi boilers emerged offering high pressure hot water without the need for a storage tank, but with low flow rates. However, British consumers holidaying abroad were beginning to experience the benefits of high pressure, high flow rate ‘power showers' and becoming more demanding in their expectations from a hot water system.  The solution was to move away from the traditional vented cylinder and move towards mains pressure hot water storage systems favoured elsewhere in the world.

Manufacturers of Domestic Unvented Systems

MODUS was set up in 1976 to lobby the UK government to make the appropriate legislative changes to allow the use of unvented hot water cylinders. In 1986 the regulations were changed and unvented systems were permitted. Since then the demand for unvented, or the alternative thermal storage option, has continued to rise significantly.