New boiler quotes in London.
Three quotes from Gas Safe registered engineers who actually cover your postcode, not a call centre eighty miles away.
- Covering EC, WC, E, N, NW, SE, SW, W and the wider Greater London
- Your job reaches them in about 60 seconds
- Three engineers maximum, then it closes
- Every one checked on the Gas Safe Register
Get three London quotes.
- Three quotes from Gas Safe engineers in your postcode
- Compare prices and opinions before you commit
- A maximum of three, then it closes
- Free to you, and no obligation
Engineers covering London.
Every one checked on the Gas Safe Register before they join.
- Gas Safe registration number verified against the public register
- A registered business with a real address, not a mobile and a van
- Coverage confirmed for the postcode areas they say they work in
- We ask homeowners how the job went, and act on the answer
You can check any engineer's registration yourself at gassaferegister.co.uk before work begins. Ask to see the card. Any decent engineer expects you to.
What a boiler swap usually looks like in London.
London is a city of flats. Census 2021 puts 40 per cent of homes in purpose-built blocks, 11 per cent in converted houses, 21 per cent terraced, 19 per cent semi-detached and only 6 per cent detached. The English Housing Survey found more than a quarter of London homes were built before 1919 and a further fifth between 1919 and 1944; Kensington and Chelsea, Hammersmith and Fulham and Haringey each have more than half their stock pre-1919. Inner boroughs such as Islington, Hackney, Lambeth and Southwark mix Victorian terraces and converted houses with council estates of the 1950s to 1970s, while outer boroughs such as Ealing, Redbridge and Bromley are dominated by inter-war semis.
In a Victorian terrace in Hackney, Lambeth or Walthamstow the boiler is usually in a rear kitchen or a first-floor bathroom, and the job is a combi-to-combi swap with a rear flue, or a conversion from an open-vented boiler and cylinder where the mains pressure can carry a combi through a tall narrow house. Converted flats need the flue terminal checked against the windows of the flats above and beside, and a long horizontal run to reach an outside wall is common. In the outer-borough semis, cylinder-to-combi conversion and system boilers with unvented cylinders for houses with loft extensions are the usual choices. Census 2021 shows 70 per cent of London households heat with mains gas only, 13 per cent electric only and 3 per cent on district or communal networks.
We deliberately don't put a figure on this page, because nobody can price a boiler from a postcode. The cost calculator will give you a realistic range for a property like yours in under a minute, and three quotes for your actual job give you the real answer.
Getting three quotes matters more on a conversion
On a straight replacement the prices tend to cluster. On a cylinder-to-combi conversion they do not: how the engineer plans to route the pipework, whether a system flush is included and what happens to the cupboard afterwards can each move the number by hundreds. Three quotes is not about haggling. It is about seeing three different opinions on how the work should be done.
Whoever you go with must be Gas Safe registered. It is against the law for anyone else to work on your gas boiler, and you can check any engineer's registration number yourself before they start.
Finding a boiler engineer in London
Our engineers cover EC, WC, E, N, NW, SE, SW, W and the wider Greater London area, and those codes are examples rather than a limit. Rather than ringing round yourself, you fill in one form and we pass it to up to three Gas Safe registered engineers who work in your postcode. They contact you, they quote, and you decide.
Ask all three the same questions
Is the price fixed or an estimate? Does it include a power flush or just a chemical clean? Is a magnetic filter included, since most manufacturer warranties require one? Who notifies building control? A good engineer in London will not mind being asked, and one who bristles has told you something useful.
Water and heating in London
Thames Water supplies most of Greater London from the chalk-fed Thames and Lee and from boreholes, and published zone readings across London run from roughly 250 to 330 mg/l as calcium carbonate, so the capital sits at the top of the hard band and tips into very hard in a number of zones. Outer boroughs are partly served by Affinity Water, SES Water and Essex & Suffolk Water, all also hard. Wherever you are in London, limescale on the hot water side of a boiler is a given and needs a scale reducer or inhibitor fitting.
Planning, flats and the edges of London
Every London borough designates conservation areas and the inner boroughs have dozens each, so a flue on a street-facing wall in a Georgian or Victorian street often needs planning consent as well as building regulations sign-off; listed terraces in Islington, Camden, Kensington and Westminster need listed building consent for any external flue. The GLA's 2024 housing stock research counts around one in nine London homes as flats in buildings of six storeys or more, and 270 buildings of 20 storeys or more, where heating is often communal and an individual boiler cannot simply be swapped. Gas is distributed by Cadent north of the Thames and by SGN south of it, and building control sits with the individual London borough for the property.
Areas of London this covers
Islington, Hackney, Camden, Lambeth, Southwark, Wandsworth, Hammersmith, Ealing, Lewisham and Walthamstow, and everywhere else in EC, WC, E, N, NW, SE, SW, W. The districts are London itself; a job just outside them still reaches engineers who cover that postcode.
London questions.
Is London tap water hard enough that a new boiler needs a scale reducer?
Yes. Thames Water draws most of London's supply from the River Thames, the River Lee and chalk boreholes, and its zone data shows hardness in the region of 250 to 330 mg/l as calcium carbonate, which is hard to very hard. When that water is heated in a combi's plate heat exchanger the calcium drops out as limescale and gradually chokes the hot water flow. Nearly every boiler manufacturer requires a scale reducer or inline inhibitor on the cold main at this level, and some make it a warranty condition. A magnetic filter on the heating return catches sludge but not scale, so both are normally fitted.
My flat is in a converted Victorian house in Islington. Where can the new boiler flue go?
The flue is usually the hard part of a London flat job. A modern fan-flued boiler needs its terminal a set distance from any opening window or door, from the boundary and from the flats above, and in a converted house those distances are tight. Most engineers look for a rear or side wall first, and where the boiler is in an internal room the flue may need to run horizontally through a cupboard or vertically through the roof. If the house is in one of Islington's conservation areas, or is listed, a terminal on the front elevation will need planning or listed building consent, so it is worth checking with Islington Council's planning team before the boiler is chosen.
What does a new boiler cost in London?
It depends far more on the job than the town. A straight combi-for-combi swap sits at the bottom of the range; a cylinder-to-combi conversion sits well above it, and only an engineer standing in your house can see which one you have. The cost calculator gives you a realistic range in under a minute, and comparing 3 quotes for your actual job gives you the real answer.
Which postcodes in London do you cover?
London is EC, WC, E, N, NW, SE, SW, W, and we match on the outward code, so a job in EC only goes to engineers who have told us they cover EC. Those districts are the town itself rather than a service boundary. If your postcode isn't listed, enter it anyway: we place jobs across the UK, not only in the towns we have a page for.
How quickly can someone come out in London?
Your job reaches engineers covering N, SE, SW, W and E postcodes within about a minute of you submitting it. How soon one of them can actually fit a boiler depends on their diary and on the job, so we don't promise a date we don't control. If your boiler has failed completely, say so on the form and it is flagged as urgent.
Are your London engineers Gas Safe registered?
Yes. Every engineer on our network is on the Gas Safe Register and we check the number against the public register before any job is sent to them. It is illegal for anyone else to work on your gas boiler. Ask to see their ID card and check it yourself at gassaferegister.co.uk before work starts.
Do you own the property in London?
This is the one thing we have to know before anything else. A boiler replacement is a permanent change to the property, so it has to be authorised by whoever owns it - which means we can only arrange quotes for the homeowner, or for someone acting on the owner's behalf. Landlords are welcome to use the form for a property they let. If you answer no, we stop there rather than pass your details to an engineer who would not be able to take the job.
Three London quotes, thirty seconds.
Free, no obligation, and only three engineers ever get your details.