System Boilers

What is a system boiler?

An example of a central heating and hot water system layout using a system boiler with an open-vented hot water cylinder

An example of a central heating and hot water system layout using a system boiler with a pressurised unvented hot water cylinder

Unlike a combi, both a system boiler and a regular (conventional) boiler work on the principle of stored hot water - but a system boiler differs from a regular boiler in some important respects.

Firstly, many of the major individual components of the heating and hot water system are built in, which means that installation is quicker, neater, easier and more efficient.

Secondly, the hot water is pumped from the boiler through the system to the radiators and hot water cylinder, resulting in a fast response and more economical running costs. The system boiler removes the need for a feed and expansion cistern.