What the price is for
A combi boiler heats the radiators and the hot taps from one wall-hung unit. There is no hot-water cylinder and no loft tank. The fitted price should cover the boiler, the flue, labour, commissioning, removal of the old boiler, and the Building Regulations notification.
Ask whether a magnetic filter, a system clean, and the controls are in that figure. Those are the items that decide whether a long warranty stays valid.
Typical fitted prices
These bands come from UK installer price guides published in 2026. They are a way to read a quote. They are not a price you can book, and London and the South East sit higher than the North for the same boiler.
| Job | Typical fitted price | What that usually means |
|---|---|---|
| Like-for-like combi swap | £1,800–£3,500 | Same position, existing pipes. Often one day. |
| Premium combi swap | £3,000–£4,500 | Longer warranty and a higher spec, still a straight swap. |
| Boiler moved | £2,600–£4,500 | New flue route and pipework. Often one to two days. |
| System or regular to combi | £3,000–£5,500 | Cylinder and tanks removed, pipes altered. |
| Back boiler to combi | £3,500–£6,000 | Fireplace unit out, a new flue, and more making good. |
The boiler on its own is often a few hundred pounds up to around £2,000. Labour, the flue, and the state of the heating system make up the rest of the fitted price.
What moves the quote
- Output. An extra bathroom needs a higher hot-water flow rate, not just a bigger heating number. See what size boiler.
- The existing system. A straight swap is one day. A conversion means pipework, a cylinder coming out, and often a chemical clean or powerflush.
- Flue and gas. A longer flue, a condensate pipe to a drain, or a larger gas supply are extra.
- Filter, scale protection, and controls. The combi guide lists what we fit so a boiler lasts. OpenTherm or other modulating controls cost a bit more and cut the gas used afterwards.
- Warranty length. Ten years and longer is often conditional on registration, a magnetic filter, and an annual service.
Running cost is separate
The quote is not the gas bill. A condensing combi only recovers heat from the flue when the water coming back is cool enough. Leaving the flow at a factory setting around 75°C throws most of that away. Lowering the flow temperature is one of the few changes that cuts the bill without buying another boiler.
Servicing
Budget about £80–£150 a year for a Gas Safe boiler service. Repairs and parts are on top of that. Manufacturer warranties usually need that annual service, and the Benchmark checklist filled in when the boiler is installed.
Before you accept a quote
- The engineer is Gas Safe registered, and the certificate is part of the price.
- The exclusions are written down: powerflush, making good, thermostat, radiator valves, a vertical flue, or a gas-pipe upgrade.
- Each quote names the same boiler model. Otherwise the totals are not comparable.
- Take three quotes. The lowest day rate with no filter is often the expensive one a few years later.
Prices are a guide to published UK fitted ranges in 2026. Installation and repairs need a Gas Safe registered engineer.