If you’re thinking about replacing your boiler, you’ll quickly come across the terms combi and system. But what do they mean, and which is right for your London home?
What Is a Combi Boiler?
A combi (combination) boiler provides heating and hot water directly from the mains. No tanks or cylinders needed.
Advantages:
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Compact – fits into a cupboard.
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Hot water on demand.
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Efficient and straightforward.
Drawbacks:
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Limited hot water flow – not great if multiple showers run at once.
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Relies on strong mains water pressure.
What Is a System Boiler?
A system boiler uses a separate hot water cylinder but no cold water tank.
Advantages:
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Handles higher hot water demand.
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Multiple taps can run simultaneously.
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Good for families or larger homes.
Drawbacks:
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Takes up more space.
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Slight delay while the cylinder reheats.
Which Suits London Homes?
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Flats and smaller homes: combi boilers fit well due to space saving.
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Large family houses: system boilers provide steady hot water for multiple bathrooms.
Both types have their place. Choosing depends on your household size, hot water needs, and available space. A qualified engineer can advise on the best fit.