UK 2026 / Reviewed October 2026
Baxi boiler replacement cost
UK, part of BDR Thermea Group
Baxi does not publish a consumer price, and BOXT, the fixed-price installer we check, does not list Baxi boilers (checked 22 October 2026). The figure that counts is a written quote; below are the model range and the warranty terms to compare quotes against.
Baxi models, prices and warranty
Installed prices are BOXT's published fixed "from" prices, which include removal of the old boiler and the installation labour. A dash means BOXT does not list a price for that model.
| Model | Type | Installed from | Warranty |
|---|---|---|---|
| 800 Combi 2 | Combi | - | 10 years |
| 800 System 2 | System | - | 10 years |
| 600 Combi 2 | Combi | - | 7 years |
| 600 System 2 | System | - | 7 years |
Warranty and what it depends on
10 years on the 800 Combi 2 and 800 System 2; 7 years on the 600 Combi 2 and 600 System 2. Baxi warranty terms
- Register within 30 days of installation
- On the 800 range, the supplied Adey filter must be fitted and registered for the 10-year term; if it is not fitted or is removed, cover reverts to 2 years
Frequently asked
How much does a Baxi boiler cost installed?
Neither Baxi nor BOXT publishes a consumer installed price for Baxi boilers, so the only reliable figure is a written quote. For context, the Energy Saving Trust puts the average cost of replacing a G-rated gas boiler with an A-rated one, with radiator valves, at £3,500 in Great Britain.
What warranty does Baxi offer?
10 years on the 800 Combi 2 and 800 System 2; 7 years on the 600 Combi 2 and 600 System 2. Conditions: Register within 30 days of installation; On the 800 range, the supplied Adey filter must be fitted and registered for the 10-year term; if it is not fitted or is removed, cover reverts to 2 years.
How do I find an accredited installer?
Baxi runs its own installer search on its UK site. Separately, check any installer at gassaferegister.co.uk and ask to see their Gas Safe ID card before work starts. The manufacturer's accredited-installer status is what unlocks the longest warranty terms.
Compare against other brands on the by-brand index. Still deciding which type? cost by type.