There are several types of boilers, each with its own advantages: combi boilers, regular boilers, system boilers, and electric or heat-only boilers. Combi boilers provide both hot water and central heating to residential properties and require no additional storage tanks or cylinders. Regular boilers require a storage tank and cylinder to provide hot water to taps and showers, while boiler systems come with built-in storage and are generally the most efficient option.