Hi Flow water systems use the power supplied by mains pressure and heat the water without the need for a header tank the insulated pressurised storage cylinder up to 310 ltr can be located conveniently to suit the property. A secondary loop can be installed to enable instant hot water from the tap without waiting for the water to unnecessarily, this also reduces water waste .

This modern an efficient way of heating the water has become popular in the last few years and OCJ now have the experience to fit this in your house or business. For more information on this way of heating water or your building contact us.

Unvented Mains Pressure Systems

  • Unvented cylinders provide mains pressure hot water.
  • In an unvented system you will be storing a large volume of hot water under pressure. For reasons of safety such systems must be installed by qualified technicians with relevant experience, CITB training and G3 certification.
  • As a precaution, pressure-relief pipework and valves must be installed to protect against unsafe pressure build-up within the vessel which could result in explosion. Pipework to vent outside the building.
  • Your Local Authority (Building Control Dept) will need to be advised of your intention to install an unvented system.
  • For reasons of safety, your system will require annual maintenance to ensure safety equipment is functioning correctly (BS2870).
  • An unvented system must be commissioned and certified by the installer. 


Vented Mains Pressure Systems

  • Thermal stores provide mains pressure hot water
  • A vented system does not store a large volume of hot water under pressure. The Thermal Store, whilst containing hot water, remains at atmospheric pressure.
  • There are no hazardous issues with a vented system. Pressure relief valves and pipework are not therefore required although a small F&E cistern is necessary for operation. This may be remote or attached to the thermal store depending on installation/operational necessities.