How do gas combi boilers work?

Gas combi boilers work by combining heating and hot water functions in a single unit. When you turn on a hot water tap, the boiler ignites the gas burner, heating water directly from the mains supply. The system uses a heat exchanger to transfer heat from the burner to the water, providing instant hot water. Additionally, it can also heat your home by circulating hot water through radiators or underfloor heating systems.