Ways to get boiler installation quotes in London, compared
- Checked September 2026
- 4 min read
- By PROS AI editorial team
Quick answer
The short version, before the detail.
A new boiler is one of the larger bills a London home produces: installers' published 2026 ranges run from about £1,800 to £4,500 fully fitted. There are four routes to a quote: a local Gas Safe registered installer who surveys your home, an online fixed-price company, a marketplace, or a request through PROS AI. This page compares them and lists what a quote must contain. PROS AI UK LTD publishes it, so read the PROS AI section with that in mind.
How many boiler quotes should you get?
Citizens Advice says to get written quotes from at least three traders before you decide. A quote is a fixed price; an estimate is a rough guess and you may end up paying more, so ask which you are being given.
What are the routes to a boiler quote in London?
| Route | Who looks at your home | How you get the price | What it costs you to ask | What to watch |
|---|---|---|---|---|
| Local Gas Safe installer | An engineer visits | Written quote after the survey | Nothing | Check the licence number yourself |
| Online fixed-price company | Nobody, or a photo or video check | Fixed price from an online questionnaire | Nothing | Non-standard installs may need a survey after all |
| Marketplace (Checkatrade, MyBuilder, Rated People, Bark) | Whoever responds visits | Each installer quotes separately | Nothing to post | Response depends on who is watching |
| PROS AI | Up to three local engineers who receive the request by text | Each engineer quotes separately | Nothing to send the request | At most three; London only |
What does a local installer's survey get you?
An engineer sees the flue position, the gas pipe size, the existing controls and the radiators before pricing. London installers' 2026 guides say Victorian and Edwardian homes often need the gas pipe upsized or the flue rerouted, and mansion blocks can need scaffolding or rope access, all of which move the price.
Before the visit, check the engineer on the Gas Safe Register: text Gas and the seven-digit licence number to 85080, or call 0800 408 5500. Anyone working on a gas boiler in a home must be Gas Safe registered; it is illegal for anyone else. The HSE reported on 14 September 2026 that 17 people had been convicted of illegal gas work since the start of 2025.
How do online fixed-price installers work?
Companies such as BOXT ask a few questions about your home online, show fixed-price quotes with no home visit, and say the quote is the price you pay. Heatable, which prices the same way, reports a median quote of £2,300 for January to May 2026. The questionnaire cannot see a corroded gas pipe or an awkward flue, so a non-standard job may be re-priced after a survey; a 2026 review says the model suits like-for-like swaps and that complex properties are better served by a local engineer.
How do marketplaces work?
You post the job free and installers respond. On Checkatrade the installer pays a monthly membership on a 12-month term; on MyBuilder the installer pays a shortlist fee when you shortlist them; on Bark up to five professionals pay credits to contact you. Rated People has been part of Checkatrade Group since 17 September 2026 and says jobs posted there are now handled by Checkatrade members. Each installer still has to survey and quote.
How does PROS AI work for a boiler quote?
You describe the job and PROS AI passes it by text to at most three local heating engineers, who contact you to arrange a survey and quote. PROS AI asks engineers for their Gas Safe registration number, but check the licence number on the register yourself. The limits: at most three engineers, no price shown online, and London only. The engineer pays PROS AI for the lead.
What must a boiler installation quote include?
Compare quotes line by line, and question any that leave these out:
- The boiler make, model and output, and whether it is a combi, system or regular boiler.
- Whether it is a quote or an estimate, and the VAT position.
- Controls that meet Boiler Plus, which applies in England to installations since April 2018: a boiler of at least 92% ErP efficiency, time and temperature controls, and for a combi one of flue gas heat recovery, weather compensation, load compensation or a smart control with automation and optimisation.
- The flue, any gas pipe upgrade, a system flush and magnetic filter, and removal of the old boiler, each stated as included or not.
- The completed Benchmark checklist at handover; a manufacturer's warranty is not valid without it.
- Notification through Gas Safe Register, so you receive a Building Regulations Compliance Certificate; keep it, because you may need it when you sell.
- The warranty length, who registers it, and the annual service it depends on.
- Payment terms. Citizens Advice says not to pay everything up front.
Fixed price or survey: which should you choose?
A fixed online price suits a straightforward like-for-like swap where you want certainty quickly. A surveyed quote suits an older London house, or a change of boiler type or position. Whichever you choose, a UK cost guide updated in August 2026 puts London £250 to £700 above the north of England, so a London quote far outside the published range deserves a question.