Boiler replacement cost in London (2026)
Prices reviewed November 2026
Allow £2,200 to £3,800 as a budgeting guide for combi boiler replacement in London; confirm the full scope and price with your contractor. A new boiler is one of the bigger plumbing costs, and the price depends on the type of boiler and the work to your system.
💷 Typical boiler replacement prices in London
| Combi boiler replacement | £2,200 to £3,800 |
| System or regular boiler replacement | £2,800 to £5,000 |
What changes the price
- The type: combi, system or regular boiler.
- The output needed for your home.
- Moving the boiler or changing the flue.
- Controls such as smart thermostats and radiator valves.
- Flushing the system and fitting a filter.
How long it takes
Replacing a like-for-like boiler usually takes one to two days. Moving the boiler or changing the system can take three to five days.
How to pay less
- Get quotes from several Gas Safe registered engineers for the same specification.
- Ask about the warranty length and what it covers.
- Keep the boiler where it is to avoid extra pipe and flue work.
Before you hire
- Ask for the installer's Gas Safe register number and check it on the register.
- Ask for a written quote that names the boiler model, flue, controls and warranty.
- Ask whether the installer registers the boiler and gives you a Building Regulations compliance certificate.
- Ask about the length of the manufacturer's warranty and what you must do to keep it.
- Ask whether the quote includes a powerflush, filter and removal of the old boiler.
💬 Questions about boiler replacement costs
Do I need a Gas Safe registered engineer?
Gas boiler work must be done by a suitably qualified Gas Safe registered engineer. Check their current registration and appliance qualifications on the Gas Safe Register before agreeing to the work.
How long does a boiler installation take in London?
A like-for-like swap is usually one day. Moving the boiler or changing the type can take two or three.
Should I get a new boiler or repair mine?
Ask an engineer to compare the fault, repair cost, parts availability and condition with the full replacement price. Age alone does not establish that replacement will save money or pay for itself.
What is included in a new boiler installation quote?
Compare the exact boiler model, controls, flue work, system clean, disposal, commissioning, VAT and paperwork. Ask whether pipe upgrades, moving the boiler or removing a cylinder cost extra.
Does a combi boiler replacement cost less than a conversion?
A like-for-like replacement in the same position usually needs less work than changing boiler type or location. Compare written specifications rather than the boiler-only price; a conversion can involve extra pipework and cylinder work.
Is it worth paying more for a better boiler?
A more efficient boiler can lower your bills, but the savings depend on your home and how you use heating. Ask the engineer to explain the running cost of each option.
Get boiler replacement quotes
Use these figures to plan your budget, then compare written quotes for the same work. Your price depends on the job, the size of your home and how soon you need it. Tell us what you need to request up to 3 local quotes; responses depend on availability.
- Get boiler replacement quotes in London
- Boiler replacement in Barking and Dagenham
- Boiler replacement in Barnet
- Boiler replacement in Bexley
- Boiler replacement in Brent
- Boiler replacement in Bromley
- Boiler replacement in Camden
- Boiler replacement in City of London
- Boiler replacement in Croydon
- Boiler replacement in Ealing
- Boiler replacement in Enfield
- Boiler replacement in Greenwich
- Boiler replacement in Hackney
- Boiler replacement in Hammersmith and Fulham
- Boiler replacement in Haringey
- Boiler replacement in Harrow
- Boiler replacement in Havering
- Boiler replacement in Hillingdon
- Boiler replacement in Hounslow
- Boiler replacement in Islington
- Boiler replacement in Kensington and Chelsea
- Boiler replacement in Kingston upon Thames
- Boiler replacement in Lambeth
- Boiler replacement in Lewisham
- Boiler replacement in Merton
- Boiler replacement in Newham
- Boiler replacement in Redbridge
- Boiler replacement in Richmond upon Thames
- Boiler replacement in Southwark
- Boiler replacement in Sutton
- Boiler replacement in Tower Hamlets
- Boiler replacement in Waltham Forest
- Boiler replacement in Wandsworth
- Boiler replacement in Westminster
Boiler replacement: like-for-like or a system change?
A combi boiler replacement in the same position is a different specification from converting a system boiler, moving the appliance or replacing a cylinder. Compare the boiler model, controls, flue work, system cleaning and disposal on every quote.
Worcester Bosch advertises an indicative Greenstar 2000 30kW FastTrack package at £2,475 including VAT and installation, subject to its package conditions. That is one supplier example, not a London market average. The ranges above are editorial budgets and do not predict the price for your home.
What should a boiler installation quote include?
Ask the installer to explain any gas-pipe upgrades, condensate route and access work before you accept. For gas work, check the engineer on the Gas Safe Register and confirm they are qualified for the appliance. Agree who handles installation notification, commissioning documents and warranty registration. Compare repair and replacement on the condition of the system; age alone does not prove a new boiler will pay for itself.
Sources and price assumptions
Researched by the HouseBFF editorial team on 2026-11-07. Published supplier prices and UK guides are examples, not a survey of London jobs or a HouseBFF quote. Check the linked source for current terms and prices.