Replacing a boiler is one of the larger one-off bills a UK household faces, and quotes can vary widely for what looks like the same job. The headline figure you see advertised is usually for a straightforward like-for-like swap. The real number depends on the boiler type, the brand, where the boiler sits, and how much extra work your system needs at the same time.
The figures below are indicative ranges for 2026 and include both the boiler and a standard installation by a Gas Safe registered engineer. Always get two or three written quotes for your own home, as prices vary by region, property and installer.
The three common domestic boiler types in the UK are the combi (heats water on demand, no cylinder), the system boiler (works with a hot-water cylinder) and the heat-only or regular boiler (works with a cylinder and one or two tanks in the loft). Within each type, the price climbs as the job gets more involved.
| Boiler type | Like-for-like swap (same spot) | Relocation or conversion |
|---|---|---|
| Combi (supply + fit) | ~£1,800 – £3,200 | ~£2,800 – £4,500 |
| System (supply + fit) | ~£2,200 – £3,600 | ~£3,200 – £5,000 |
| Heat-only / regular (supply + fit) | ~£2,000 – £3,400 | ~£3,000 – £4,800+ |
Indicative supply-and-fit ranges, 2026. A "conversion" means changing system type, for example moving from a heat-only boiler and cylinder to a combi, which adds pipework and removal labour.
Two homes can get very different quotes for the same boiler type. The main drivers are:
A common point of confusion: the government's Boiler Upgrade Scheme grant in England and Wales is for low-carbon heating such as air source and ground source heat pumps (and biomass in some cases). It does not apply to a replacement gas combi, system or heat-only boiler. If you are replacing a gas boiler with another gas boiler, you will not qualify for that grant. Heat-pump grants are a separate decision with their own running-cost and installation considerations.
A new boiler is a big outlay, so it is worth weighing it against a repair. As a rough guide, if your boiler is well over ten years old, has had repeated breakdowns, or a single repair quote is approaching half the cost of a new unit, replacement often makes more financial sense. Our guide on repairing or replacing your boiler walks through the trade-offs in detail.
Boiler cover (and breakdown insurance) generally pays for repairs and call-outs on an existing, working boiler, not for a planned replacement of an old or end-of-life unit. Most policies exclude boilers above a certain age and won't fund a full upgrade. What cover can do is reduce the sting of repair bills while your current boiler still has life in it, and some policies include an annual service that helps it last longer. If you're weighing up the value, see is boiler cover worth it? and read what boiler cover actually includes before you buy.
A like-for-like combi swap is typically around £1,800 – £3,200 supplied and fitted, with premium brands and any extra pipework, flue or flush work pushing it higher. Relocating or converting the system can add £800 – £1,500 or more.
A straightforward like-for-like swap is usually done in a day. A conversion (for example heat-only to combi), a relocation, or a job needing a powerflush or roof flue can take two days or more.
Not through the Boiler Upgrade Scheme — that grant is for heat pumps and other low-carbon heating, not replacement gas boilers. Eligibility for any other support depends on your circumstances, so check the official guidance for your nation.
Generally no. Cover is designed for repairs and breakdowns on a working boiler, not planned replacement of an old unit, and most policies exclude boilers over a certain age. It can, however, soften repair costs while your current boiler is still serviceable.
Many gas boilers last around 10–15 years with regular servicing. Frequent breakdowns, parts becoming hard to source, or rising repair costs are signs it may be more economical to replace than keep repairing.
If your boiler still has life left, cover can keep repair bills predictable. Compare policies from our selected panel of providers in minutes.
Compare boiler coverAll prices are indicative ranges for the UK in 2026 and will vary by property, region and installer. This article is information, not financial or installation advice. We compare cover from a selected panel of providers, not the whole market, and may earn a commission. Always obtain written quotes and use a Gas Safe registered engineer for any boiler work.