Heating · Updated 2026
Boiler replacement cost
Typical range£1,500–£8,000· Average combi boiler replacement (like-for-like)
New combi, system and conventional boiler prices for 2025. In the UK, expect to pay between £1,500 and £8,000, with the typical project around £2,500 (average combi boiler replacement (like-for-like)). Regional variation, specification tier and site access conditions all shift the final quote.
Quick answer: Boiler replacement cost in the UK typically costs between £1,500 and £8,000 (Average combi boiler replacement (like-for-like)). London and the South East run 20–35% above this range; the North, Wales and most of Scotland sit 5–15% below.
Homeowners researching this typically also price up bathroom renovation cost. For wider context, browse our bathroom pricing, kitchen pricing and trades day rates.
Cost table
Indicative price ranges (UK, GBP)
| Item | Typical range (GBP) |
|---|---|
Budget combi (like-for-like swap) — Entry-level brand, same location | £1,500–£2,200 |
Mid-range combi boiler — Worcester/Vaillant, 5–7 yr warranty | £2,000–£3,200 |
Premium combi boiler — 10-year warranty, A-rated efficiency | £2,800–£4,500 |
System boiler replacement — With existing hot water cylinder | £1,800–£4,000 |
Conventional / heat-only boiler — Older systems with tanks in loft | £2,000–£5,000 |
Boiler relocation — Moving boiler to new location | £3,000–£6,000 |
Labour costs
Labour typically accounts for 40% of the total project cost in the UK.
Labour line items
| Item | Typical range (GBP) |
|---|---|
Gas Safe engineer (per day) | £250–£400/day |
Removal of old boiler | £100–£250 |
Fitting new boiler | £600–£1,200 |
Flue installation | £200–£600 |
Magnetic system filter | £0–£0 |
Materials costs
Materials and fittings make up the remainder of the budget, with specification tier driving most of the variation.
Materials & fittings
| Item | Typical range (GBP) |
|---|---|
Budget combi boiler unit | £700–£1,200 |
Mid-range combi unit | £900–£1,500 |
Premium combi unit | £1,400–£2,500 |
Magnetic filter (Magnaclean) | £60–£120 |
Flue kit | £80–£200 |
Thermostat / smart control | £50–£250 |
Factors affecting cost in the UK
- ·Region — London and the South East run 15–30% above national averages.
- ·Specification tier — premium materials and finishes can double the base cost.
- ·Access and site conditions — flats, restricted parking and listed buildings add time.
- ·Scope changes mid-project — late design decisions are the biggest cost overrun driver.
- ·Trade availability — quotes rise 10–20% in peak spring and summer months.
Ways to reduce cost
- ·Stick with the same boiler position and fuel type to avoid pipework changes.
- ·Get fixed-price quotes from three Gas Safe engineers via Heatable, BOXT and a local independent.
- ·Choose a 7- to 10-year warranty boiler over a 12-year — the price gap rarely pays back.
- ·Combine boiler replacement with rad valve and thermostat upgrades for a single visit.
- ·Book in spring or summer when installers offer off-peak discounts.
Frequently asked questions
- How long does a boiler last?
- A well-maintained gas boiler lasts 10–15 years. Worcester Bosch and Vaillant boilers are among the longest-lasting. Annual servicing (£70–£120/year) significantly extends boiler life and is usually required to maintain the warranty.
- Should I get a combi or system boiler?
- Combi boilers heat water on demand without a cylinder — ideal for smaller homes (up to 3 bed, 1 bathroom). System boilers use a hot water cylinder and suit homes with multiple bathrooms or high hot water demand. Conventional (heat-only) boilers are being phased out in new installations.
- What are the best boiler brands in the UK?
- Worcester Bosch is consistently rated the best brand for reliability and customer satisfaction, followed by Vaillant, Baxi, and Ideal. Which? regularly surveys homeowners on boiler brands.
- Are smart thermostats worth it?
- Yes — a smart thermostat (Nest, Hive, Drayton Wiser) can save 10–15% on heating bills. Installation costs £150–£300 and the payback period is typically 1–2 years.
- Is there VAT on a new boiler?
- There is 0% VAT on installing a new gas boiler in an existing domestic property for energy efficiency purposes. Always confirm with your installer as the rules changed in 2022 (Energy-Saving Materials VAT relief).