What is a Combi Boiler?

A combi boiler provides heating and hot water directly from the boiler.

Here’s an example of a central heating and hot water system layout using a combi boiler:

A 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.

A combi boiler is both a high-efficiency water heater and a central heating boiler, combined (hence the name) within one compact unit. Therefore, no separate hot water cylinder is required, offering space saving within the property.

Further benefits of a combi boiler are significant savings 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 boiler 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.

Thanks to Worcester for this article