Bosch Thermotechnology
A combination or ‘combi’ boiler is both a high efficiency water heater and a central heating boiler in a single compact unit. Combi boiler installations also require less pipework, reducing the initial costs and the chances of a leaking pipe. About 70% of UK homeowners choose combi boilers over conventional boilers citing its efficiency and compact design as the key desirable features. Combi boilers are hooked to the mains water supply and provide instant hot water on demand. For example, changing from an E-rated boiler to a new A-rated combi in a mid-floor flat only saves 55 pounds a year on gas; replacing an F-rated boiler in a detached house, however, could save 210 pounds.