System Boiler in Gunnersbury

With so many different types of  system boilers it can be a minefield to know which one is best suited to your particular circumstance, many variables come into play when choosing a boiler and should only be done by a competent specifier and installer. Be sure to visit our Boiler Buying Guide for more information on choosing a boiler.


A system boiler is similar in some respects to a regular boiler in that they both work on the principle of stored hot water. However, they differ in one important respect in that a system boiler does not require a feed and expansion tank. This frees up valuable space in the loft and results in a cheaper, neater and more efficient installation. Unlike a combi boiler you still require a hot water tank, usually within the airing cupboard so you can still benefit from a full tank of hot water and a useful area for drying towels. Another advantage of a system boiler over a regular type is that hot water is pumped directly from the boiler around the radiator system and hot water tank, this results in a faster response time and lower running costs.
A system boiler tends to be larger than a regular boiler as it contains the expansion vessel, filling loop and pump, however, many advantages including simple installation as most of it is pre-plumbed, pre-wired and tested prior to delivery.


A regular central heating system consists of a boiler unit, separate controls, a feed tank, expansion cistern and a hot water cylinder usually in the airing cupboard. If you’re intending to replace an older boiler it’s more than likely that it will be a regular type system, this differs between a system boiler or combi boiler system as it takes up most space out of all 3 but its probably the most efficient.


It’s important to seek professional advice on which boiler is best suited to your requirements, in general a system boiler is a good choice if you have no room in the loft for an expansion tank and have a large family wishing to take hot water from several different sources at once, but remember, take advice form a professional and arrange for more than just one quote. Have a look at the table below for pros and cons.