what is a system boiler
A system boiler heats your central heating system directly and produces hot water for your cylinder. A system boiler, just like a regular (conventional) boiler works on the principle of stored hot water.However, a system boiler differs from a regular boiler in some important respects.n example of a central heating and hot water system layout using a system boiler with an open-vented hot water cylinder. View our system boilers. An example of a central heating and hot water system layout using a system boiler with a pressurised unvented hot water cylinder. View our system boilers.