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Cost guide · 2026

How much does central heating cost in the UK?

A full new central heating system, with a boiler, radiators and pipework, typically costs £3,500 to £6,000 in the UK, while replacing just the boiler is £2,000 to £3,500. What you pay depends on whether you are swapping a boiler, adding radiators or underfloor heating, or moving to a heat pump. The table below breaks down what each part costs on our guide prices.

JobFromTypicalUp toPriced by
New boiler£1,800£3,000£4,500supplied and fitted
Radiator replacement£110£180£350per radiator
Underfloor heating£50£90£150per m²
Air source heat pump£7,000£11,000£18,000before grant
Power flush£300£500£1,000for the system

What changes the price of central heating

The boiler is the biggest single item in most heating jobs, and the price turns on the type (combi, system or regular), the output you need and how much the flue and pipework have to be moved. A like-for-like swap in the same spot is the cheapest; relocating the boiler or converting from one type to another costs more.

Beyond the boiler, radiators, a power flush to clear sludge, and underfloor heating each add to the bill, and an older system may need new pipework. An air source heat pump is a different route again, higher upfront but eligible for a government grant, and it suits a well-insulated home with room for larger radiators or underfloor heating.

Explore each cost in detail

Common questions

How much does a new central heating system cost?

A full new system, with a boiler, radiators and pipework fitted from scratch, typically costs £3,500 to £6,000 in the UK. Replacing just the boiler on an existing system is £2,000 to £3,500, and adding or swapping individual radiators or a power flush costs less again. The table above breaks each part down.

Is it cheaper to replace radiators or the whole system?

Replacing individual radiators is much cheaper than a whole system and is often all an older setup needs, especially alongside a power flush to clear sludge. A full system replacement only makes sense if the boiler and pipework are failing too. Price the boiler, radiators and a flush separately using the guides above.

How much does an air source heat pump cost compared to a boiler?

An air source heat pump costs more upfront than a gas boiler, typically several thousand pounds more before the government grant, which brings the gap down. It suits a well-insulated home with larger radiators or underfloor heating. A straight boiler replacement is cheaper today, but running costs and grants change the long-term picture.

These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing. The underlying figures are free to download as a CSV under a CC BY 4.0 licence.

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