There are five types of combi boiler. These are instantaneouscondensing, instantaneous, storage condensing, storage and CombinedPrimary Storage Units. Instantaneous are the most common types as theyallow instant access to hot water. The instantaneous condensing type isa little more efficient. Combined Primary Storage Unit types are aspecial category of combi, which incorporates a very large water storeallowing for higher water pressure, faster water flow, and for yourradiators to heat more quickly.

In smaller dwellings, theinstallation of a compact combination boiler can be a great way toconserve space. With a combi boiler, a balanced flue, some pipes, and afew radiators, you have all the necessary components of a fully-fledgedcentral heating system. With a combi boiler, there is no need for anadditional water pump, feed and expansion cistern, or water tank.

Fora long time, combination gas boilers have been more popular in mainlandEurope than in the UK, but this has changed in recent years, to theextent that it is now the most commonly installed type. Combi boilersuse essentially the same technology as standard boiler, but there are anumber of functional differences between the two.

All thewater used in a heating system which uses a combination boiler issealed in, negating the requirement for a feed and expansion cylinder.Combination boilers have their own internal hot water tank, whichcannot store as much as a separate tank, but that should provesufficient for smaller homes.

A combination boiler is able toprovide instant hot water by using the heat from the central heatingsystem to heat freshly drawn water.

Due to the fact that theboiler has to switch over to supply hot water to the taps, the centralheating is turned off while the hot water is flowing. By turning offthe hot tap, you are turning back on the central heating.

Althougha combi boiler has some disadvantages over a regular boiler, in thatthe central heating is not constant, and you cannot draw hot water frommore than one source at a time, the space saving advantages faroutweigh these disadvantages in smaller homes. Furthermore, combinationboilers tend to be a good deal cheaper than their componentcounterparts, so you could up saving money as well as space with one ofthese flexible units.


British Gas can help you to save money on a central installation. By replacing your old boiler with one of our central heating boilers such as the energy efficient range of , you could save up to 40% on your bills.