A combi boiler, short for combination boiler, is a type of boiler that provides both hot water and central heating in one compact unit. It is designed to combine all components of a traditional central heating system into one package to save space and money. Combi boilers use condensing technology to efficiently heat the system water by extracting latent heat from the flue gases. When you require heating or hot water, a gas burner in the combi boiler is ignited, and the heat from the flame is transferred via the main heat exchanger to the primary circuit, at which point the heat is moved to either directly to the radiators or to your hot water taps via a plate heat exchanger. Combi boilers are highly energy-efficient and financially efficient because they supply hot water on demand, so you only pay for what you use. They are popular with apartment and condominium owners, and homeowners in regions where homes do not have basements because they require little space and can be installed in spaces not much larger than a broom closet. However, combi boilers may not be suitable for larger homes because they take water directly from the mains, and the water pressure will drop rapidly if multiple taps and showers are turned on at the same time.