Quick answer: Replacing a boiler costs a modelled UK average of £2,804 in July 2026, with a typical range of £1,823 to £4,346. Swapping an old, inefficient unit could save up to £321 a year on gas (estimate) — a modelled payback of around 9 years.
Boilers remain the heating workhorse of most UK homes, and with gas prices up sharply this quarter the cost of an inefficient one is rising too. Here are the numbers from our UK Home Energy Cost Index; our boiler guide covers the choice between combi, system and regular models — see the combi boiler glossary entry if the terms are new.
Key boiler statistics for 2026
- A new boiler costs a modelled UK average of £2,804 installed — Green Reach Energy Cost Index, July 2026 (modelled).
- Typical boiler replacements range from £1,823 to £4,346 depending on boiler type and complexity — Green Reach Energy Cost Index, July 2026 (modelled).
- London is the most expensive region for a boiler swap at a modelled £3,365 — Green Reach Energy Cost Index, July 2026 (modelled).
- Northern Ireland is the cheapest at £2,580, followed by the North East at £2,608 — Green Reach Energy Cost Index, July 2026 (modelled).
- The regional spread between London and Northern Ireland is £785 — Green Reach Energy Cost Index, July 2026 (modelled).
- A North West installation averages £2,664; the South East £3,140 — Green Reach Energy Cost Index, July 2026 (modelled).
- Upgrading an old, inefficient boiler could save up to £321 a year on gas (estimate) — Green Reach Energy Cost Index, July 2026 (modelled).
- Modelled simple payback on a replacement boiler is around 9 years — Green Reach Energy Cost Index, July 2026 (modelled).
- A new boiler is the fourth-cheapest upgrade in our index — roughly a quarter of the pre-grant cost of a heat pump (£11,014) — Green Reach Energy Cost Index, July 2026 (modelled).
- Gas costs 7.33p/kWh under the July–September 2026 Ofgem price cap, with a 29.04p/day standing charge.
- The typical dual-fuel household now pays £1,862 a year, up 13.5% on the previous quarter — Ofgem, July 2026.
- ECO4 — the main route to free boiler replacements — closed to new applications in March 2026 — GOV.UK, checked July 2026.
Boiler replacement costs by UK region
The table applies our regional labour index to the national baseline. As with every product we model, London tops the table and Northern Ireland sits at the bottom.
| Region | Modelled average installed cost | vs UK average |
|---|---|---|
| UK average | £2,804 | — |
| London | £3,365 | +20% |
| South East | £3,140 | +12% |
| East of England | £2,972 | +6% |
| South West | £2,944 | +5% |
| West Midlands | £2,748 | −2% |
| East Midlands | £2,720 | −3% |
| Scotland | £2,692 | −4% |
| Yorkshire & the Humber | £2,664 | −5% |
| North West | £2,664 | −5% |
| Wales | £2,636 | −6% |
| North East | £2,608 | −7% |
| Northern Ireland | £2,580 | −8% |
All modelled figures on this page come from the Green Reach Energy Cost Index — our July 2026 estimates built from national installed-price baselines and regional labour indices, not quotes for your specific home. Real boiler installation prices vary with property type, spec and installer, so treat these as a starting point and read how we calculate costs for the full method and its limitations.
Grants: the honest picture
There is currently no national grant for a like-for-like gas boiler replacement. ECO4, which funded free boiler swaps for eligible households, closed to new applications in March 2026, and the Great British Insulation Scheme closed the same month. Government funding has shifted decisively towards heat pumps — £7,500 via the Boiler Upgrade Scheme — and towards whole-home upgrades through the Warm Homes: Local Grant for lower-income households in EPC D–G homes. Our guide to every energy grant still open in 2026 has the full picture.
If you are weighing a new boiler against a heat pump, compare both routes side by side with the savings calculator.
Download the dataset
The full Cost Index — 9 upgrades × 12 UK regions, July 2026 — as CSV: gre-cost-index.csv. Free to reuse with attribution (CC BY 4.0) — please credit Green Reach Energy and link the methodology. Figures are modelled estimates, not quotes.