A system boiler is a type of heating system that provides hot water and central heating directly from the boiler. It is designed to work with a sealed system, meaning it doesn't require a water tank in the loft. Instead, it uses a hot water cylinder to store hot water, making it suitable for homes with higher hot water demands. System boilers are efficient and can supply hot water to multiple taps simultaneously. They are often favored for their compact design and ease of installation. Additionally, they can be combined with renewable energy sources, such as solar panels, to enhance energy efficiency.