Combi (or combination) boilers are the UK's most popular type of boiler for gas central heating and domestic hot water. They are easy to install, simple to use and economical to run.
A combi boiler only heats water when a hot top or shower is turned on, ensuring maximum efficiency. There is no need to find space for a water storage cylinder or have a tank in the loft. Hot water is delivered to your taps at mains pressure, so you can enjoy a powerful shower without the need for a pump.