System

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

With a system boiler many major components of the heating and hot water system are built in - so installation is quicker, neater, easier and more efficient. These boilers also include an expansion vessel, so there's no need for a feed and expansion tank in the loft.