SYSTEM BOILERS
The major components of the heating and hot water system, including the pump and expansion vessel, are built into the system boiler, and a sealed hot water cylinder in the system provides hot water for the taps and heats the radiators. There is no need for a feed or expansion cistern in the loft, which saves space and eliminates the risk of any leaks or frost damage to pipes and tanks.
If you live in a home with more than one bathroom or you require more hot water than can be provided by a combi boiler, then a system boiler could be your perfect heating and hot water solution.