Boiler Replacement Cost Calculator UK
Get a 2026 UK boiler replacement estimate in 30 seconds. Choose brand tier, boiler type and install scope for an instant low/mid/high figure — Worcester Bosch, Vaillant, Baxi and Ideal pricing with regional labour rates, supply-and-fit incl. VAT. No email required.
Estimate Your Boiler Replacement Cost
4 steps. Supply-and-fit including the boiler, flue, filter, labour, gas safety check, certification and VAT.
How This Calculator Works
We combine brand tier, boiler type and install scope with 2026 UK Gas Safe supply-and-fit rates, then apply a regional labour multiplier. As a worked example, a mid-tier Worcester 4000 like-for-like combi swap sits near £2,500 fitted at the Midlands baseline; take that same job to London and the 1.28 multiplier lifts it to about £3,200 before the ±20% band. The most common pitfall is treating a system-to-combi conversion as if it were a straight swap – ripping out the cylinder and tanks, running new gas and adding a filter and flush can add £1,000–£2,000 that a like-for-like price never carries, so tell the installer exactly what you have now. If you're also refreshing the wider system, our central heating installation cost guide and boiler service cost guide show where the rest of the budget goes.
Brand & Install (supply + fit)
- Budget tier — £950 (Baxi, Ideal Logic)
- Mid tier — £1,350 (Worcester 4000, Vaillant Plus)
- Premium tier — £1,800 (Worcester 8000, Viessmann)
- Like-for-like swap +£1,150 · System change +£2,400 · New install +£3,500
- System boiler ×1.10 · Regular ×1.05
Includes boiler, flue, magnetic filter, labour, gas safety check, certification and VAT.
Regional Multipliers
- London 1.28× · South East 1.14× · South West 1.05×
- East of England 1.08× · Midlands 1.00× (baseline)
- North West 0.93× · North / Yorkshire 0.92×
- Wales 0.94× · Scotland 0.96× · NI 0.88×
Low/high band is ±20% around the mid estimate. A firm price follows a home survey.
Typical Boiler Replacement Costs (2026)
Combi-boiler supply & fit by brand tier and install scope, Midlands baseline (±20% band).
| Job (combi) | Mid estimate | Cost range (fitted) |
|---|---|---|
| Budget brand, like-for-like swap | £2,100 | £1,680–£2,520 |
| Mid brand (Worcester 4000/Vaillant), like-for-like | £2,500 | £2,000–£3,000 |
| Premium (Worcester 8000/Viessmann), system change | £4,200 | £3,360–£5,040 |
| Mid brand, new install (no existing system) | £4,850 | £3,880–£5,820 |
These figures power the calculator above — enter your own spec for a tailored estimate. For the full breakdown, read our complete cost guide.
Frequently Asked Questions
How much does a new boiler cost in 2026?
Why do Worcester quotes vary so much?
What is the Boiler Upgrade Scheme (BUS)?
Should I get a magnetic filter fitted?
How long does a boiler installation take?
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Why is my real boiler quote different from the calculator?
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