An Unvented Hot Water Cylinder is a pressurised system which is fed directly from the cold mains water feed and therefore can deliver

hot water at mains pressure, which is great for improving the performance of your shower and bath.

Unvented Cylinders don’t require a cold water storage tank, which is ideal if you are pushed for space 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. If you are considering using multiple fuel sources, you may wish to consider a thermal store.

Unvented hot water cylinders require expansion vessels to be fitted to allow the expansion of water in the system as it heats up. Unvented cylinders also come with other safety mechanisms, such as pressure relief valves and twin thermostats.