In 2026 most like-for-like combi boiler replacements in the UK cost roughly £1,800 to £3,200 fitted, and prices in London typically run 10 to 20% higher. A more involved job, such as converting to a combi or moving the boiler to another room, can approach £6,000 or more. This guide explains where those numbers come from, what pushes a quote up or down, and what a good quote should include, so you can compare prices with confidence before booking a new boiler installation.
Typical new boiler prices in 2026
The boiler itself is usually less than half of the final bill. Most of the difference between quotes comes from labour and from how much work your property needs. As a guide, these are the typical fitted prices published across the UK market this year:
| Type of job | Typical UK price (fitted) |
|---|---|
| Like-for-like combi boiler swap | £1,800 – £3,200 |
| Premium-brand combi with a longer warranty | £3,000 – £4,000 |
| Converting to a combi, or moving the boiler | Up to £6,000 or more |
| London and the South East | Typically 10 – 20% higher |
System and regular boiler replacements usually sit above a simple combi swap, because there is a hot water cylinder and more pipework involved. If the cylinder also needs replacing, or you are switching to an unvented cylinder for mains-pressure hot water, expect the price to rise accordingly.
Why boilers cost more in London
Labour rates are higher in London, and so are the practical costs of working here: parking, congestion charges in central areas and the time it takes to move between jobs. The housing stock plays a part too. Many homes in Islington, Highbury and Hackney are Victorian houses split into flats, where finding a compliant flue route, working around shared supply pipes or carrying a boiler up several flights of stairs all add time.
Further out, in areas such as Chingford, Walthamstow, Enfield and Loughton, many homes are 1920s and 1930s houses that still have a regular boiler with tanks in the loft. Those homes often benefit from a combi conversion, which costs more up front than a straight swap but frees up space and gives you hot water on demand.
What affects the price of a new boiler
These are the main things that move a quote up or down:
- Boiler type and size: combi, system or regular, and the output (kW) needed for your home.
- Brand and warranty: premium brands with 10 to 12-year warranties cost more than entry-level models with shorter cover.
- Location: keeping the boiler in the same place is cheapest. Moving it means new pipework, a new flue and often a new condensate route.
- System change: converting to a combi involves removing the cylinder and loft tanks and capping off old pipework.
- Gas supply: combis often need a larger gas pipe than older boilers, which may need upgrading back to the meter.
- Flue: a horizontal flue through an outside wall is simplest. Vertical flues, extended flues and plume kits add cost.
- Cleaning the system: a chemical flush is standard, but a heavily sludged system may need a power flush.
- Controls: a basic programmer costs less than a smart thermostat with app control.
What should be included in a boiler quote
A cheap quote is not a good deal if important items are missing. A proper quote for a new boiler should include:
- The boiler and flue, plus all fittings and pipework
- Removal and disposal of the old boiler (and cylinder or tanks if it is a conversion)
- A system flush to clean the radiators and pipework
- A magnetic filter to protect the new boiler from sludge
- Heating controls
- Commissioning and testing
- Registration with Gas Safe, which notifies Building Control on your behalf
- Registration of the manufacturer's warranty
Every boiler installation we quote for includes a system flush, a magnetic filter and controls as standard, with a fixed price agreed before any work starts.
How to compare boiler quotes
- Compare like with like: the same boiler type, output, warranty length and included extras.
- Check the warranty terms: most require an annual service to stay valid.
- Check the engineer is on the Gas Safe Register before they start. You can search the register online at gassaferegister.co.uk.
- Ask whether the price is fixed after the survey, or whether extras could be added on the day.
- Be wary of quotes that skip the system flush or filter. They save money now but shorten the life of the new boiler.
Should you repair your old boiler instead?
If your boiler is under ten years old and the fault is a single part, a boiler repair is usually the better value. If it is older, keeps breaking down or parts are getting hard to find, replacing it often makes more sense. Our guide to the signs you need a new boiler goes through how to decide.
Getting a fixed-price quote in London
The only way to know exactly what your new boiler will cost is a survey of your home. We give free, fixed-price quotes across North and East London, including Islington, Hackney, Chingford, Walthamstow, Enfield and Loughton, and the price we quote is the price you pay. Find out more about our new boiler installations, or get an instant quote online.