Unvented Cylinders


Unvented Mains Pressure System -The system is fed directly from a water mains supply giving better draw off points throughout the house (taps etc).


  • High water pressure (usally 3.5 bar).
  • Balanced hot and cold pressures at the taps and valves.
  • Better hot and cold water performance with increased flow rate.
  • No water storage cistern or pipework in the loft - this gives more storage space and no chance of frost damage to pipe work.
  • Cleaner water - Water is not stagnating so is more hygenic, due to the fact here is no water storage cistern.
  • Less rigidity ie. more installation options for where the cylinder can be sited.
  • In a renovation or new build the system is quicker to install as no extra piepwork or systems are required within the loft.
  • The majorioty of cylinders are made from stainless steel and carry a 25 year manafactuers guarantee.

Requirements/considerations for an effective system

  • Mininmum of 2 bar from the incoming mains supply is required, a 3.5 bar pressure or above is however recommended.
  • The incoming main should be at least 25mm.
  • Before installation commences it would be recommened that the local water authority is contacted to ensure there are no planned pressure reductions within your area.

The information below provides further images and technical infomation from the companies recommended by DK Plumbing.