A combi boiler is a type of heating system that combines both a central heating boiler and a hot water heater in one unit. This means it can provide heat for your home and hot water for your taps without needing a separate water tank. Combi boilers are popular because they save space and are energy-efficient, making them a great choice for smaller homes. These boilers work by heating water directly from the mains supply when you turn on a tap. This on-demand system means you won’t run out of hot water, and it can help reduce energy bills since you only heat water when you need it.