There are 3 different types of high-efficiency condensing boiler:
| Combi |
| Regular (a regular boiler is often also referred to as a “traditional” or “conventional” boiler.) |
| System |
Each type delivers all the benefits of high-efficiency technology, but which one you choose will depend on several factors, including your property, your lifestyle and the professional advice of a Gas Safe Register (Great Britain) or CORGI (N. Ireland and Channel Islands) installer for gas boilers, or, an OFTEC registered installer for oil-fired boilers.
An example of a central heating and hot water system layout using a combi boiler
The high efficiency condensing combi or combination boiler is an ingenious space-saving idea, and an increasingly popular choice in UK homes. In fact, combis now account for well over half of all the new domestic boilers installed in Britain every year.
The major difference between a combi and any other type of boiler is that a combi eliminates the need to store hot water - so no hot water cylinder in the airing cupboard. It is both a high-efficiency water heater and central heating boiler, combined (hence the name) within one compact unit which usually sits in the kitchen or utility room, or sometimes in the airing cupboard. The space savings result from the fact there is no hot water storage cylinder, cold water storage cistern or other familiar components of a regular (conventional) heating system.
The further benefits of this are a significant saving on hot water costs, and the fact that hot water is delivered through your taps or shower at mains pressure. So you can enjoy powerful showering* without the need for a pump. Another combi benefit is that it can generally save you money on installation time and costs, since no tank in the roof space means less pipe work and a shorter installation time.
*a thermostatically-controlled shower safeguards against sudden changes in water temperature.
| Consideration | Most suitable boiler |
|---|---|
| You want to use your loft space for a room conversion or other purpose | COMBI |
| You live in a flat or bungalow (i.e. have very little or no roof space) | COMBI |
| Your home has more than 2 bathrooms | REGULAR OR SYSTEM |
| Your main water pressure is low | REGULAR OR SYSTEM |
| You want to replace an old boiler to improve an existing conventional central heating system | REGULAR, SYSTEM or COMBI |
| There is a need to have hot water available on tap without waiting for it to heat up. | COMBI |
