Combi Boiler Guide
Combi – short for "combination" – boilers are the most popular form of boiler in the United Kingdom, accounting for more than 50% of new condensing boiler sales. A combi boiler is, as the name suggests, a highly efficient water heater and central heating boiler combined in a single unit.
Water is heated on demand from within the unit itself, so a combi boiler (unlike a conventional boiler -- which typically requires a copper cylinder in an airing cupboard or elsewhere to store hot water) can be a practical solution if space within your home is at a premium. Combi boilers are typically compact; they can be hung conveniently on a kitchen wall, for example ; and their installation is less disruptive and less expensive than that of conventional boilers.
The absence of a storage cylinder means that significant savings on water heating can be made. Although the rate at which hot water is produced may be slightly slower than with a conventional boiler, hot water is nevertheless delivered through your taps or shower head at mains pressure. This may mean that you can enjoy a high pressure "power" shower without the need for an additional pump.
A condencing combi boiler is a popular option, adding extra efficiency to the – already not insignificant – benefits of a standard combi boiler. A condensing combi boiler can be installed in exactly the same way as its standard counterpart and can thus be a direct replacement for an existing boiler if desired.