Unvented hot water cylinders are pressurised systems which are fed directly from the cold mains water feed.  Therefore they can deliver hot water at mains pressure, which greatly improves the performance of your shower and bath.

Unvented cylinders don't require a cold water storage tank, which is ideal for tighter spaces as well as offering more flexibility when siting the cylinder.

The water can either be heated directly via an immersion heater or indirectly via the central heating system, solar thermal technology or other renewal energy such as heat pumps and biomass.