Unvented Hot Water

Unvented Hot Water

Unvented Hot Water Systems are often chosen as an upgrade to conventional (boiler/cylinder) systems, because in many ways the operating principles of the heating are the same.

The only real difference is that you loose the water tank in the loft space and the mains water pipe feeds directly to the cylinder.

This set up provides optimum hot water performance because both hot and cold water supplies are now at mains pressure (3 bars) to every outlet in the property.

These systems are normally used in larger dwellings because they pretty much eliminate water starvation and are capable of running three, maybe four baths simultaneously. It is quite common to find them in new houses, even one bedroom flats but most people have these changed to combination boiler as they believe it to be wasted energy heating in excess of 125 litres of water to run one bath.


  • Balanced Pressures at hot and cold taps
  • High performance showering throughout the house
  • High Pressure and flow rates at an average of 20 litres/minute
  • Fast filling baths
  • Potable (drinking) water at all taps
  • Quiet running and fast recovery time (basically 15-20 minutes to heat 125 litres)
  • No cold water storage - No chance of contamination.


  • No storage back up if cold mains fails
  • Poor mains pressure will cause poor performance
  • The need for a discharge (overflow) pipe work requires slightly higher level of maintenance

For more information on Unvented Hot Water or to book a quote to upgrade your current system, please fill out the quotation form online or contact us.