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AnswerCombi vs system boiler: which is best?
A combi boiler heats water on demand with no tank — ideal for smaller homes. A system boiler uses a hot-water cylinder and suits larger homes with multiple bathrooms.
In more detail
If two showers run at once, a system boiler (or heat pump with cylinder) is usually better.
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2026 figures, based on Energy Saving Trust, Ofgem & gov.uk data · always confirm with a professional survey.