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⭐ EssentialBoiler & Heating System
Which Type of Boiler Do You Have?
There are three main types of boiler used in UK homes. Knowing which you have makes an enormous difference when describing a problem to a plumber or getting a quote.
🔥 Combi Boiler
The most common type in the UK. Provides both central heating and hot water directly from the mains — no storage tank or cylinder. Hot water is heated on demand as you open a tap.
You have a combi if: You have no hot water cylinder and get instant hot water from taps.
🪣 System Boiler
Works with a separate hot water cylinder (usually in an airing cupboard). The boiler heats the cylinder which stores hot water. Cold water comes directly from the mains — no loft tank.
You have a system boiler if: You have a cylinder in an airing cupboard but no cold water tank in the loft.
🏠 Conventional (Regular) Boiler
The oldest type. Has both a hot water cylinder AND a cold water storage tank in the loft. Common in homes built before the 1990s.
You have a conventional boiler if: You have a cylinder AND a tank in the loft, and your bathroom cold taps have lower pressure than the kitchen.
Why this matters for quotes: Saying "I have a combi boiler" vs "I have a system boiler with a cylinder" tells the engineer what parts to bring and how long the job will take.
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General guidance only — not a substitute for professional advice. Always consult a qualified engineer if you are unsure. Gas work must only be carried out by a Gas Safe registered engineer. Unvented (pressurised) hot water systems must be worked on by a G3-qualified engineer. We accept no liability for any loss, damage, or injury arising from the use of this information.
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