Company lists · Data refreshed September 2026

Top 25 Condensing boiler manufacturers based in the United Kingdom

Name: Condensing boiler manufacturers based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 193 companies tracked

RevenueBase identified 193 condensing boiler manufacturers headquartered in the United Kingdom as of September 2026 and tracks 3,497 professional contacts across them, including 807 with verified work emails. London is the largest hub.

This list covers condensing boiler manufacturers headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 16, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 16, 2026 86% judged on-target in blind review

193Companies

3,497Contacts tracked

807Verified emails

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The 25 largest condensing boiler manufacturers based in the United Kingdom

Ranked by team size

Top 25 of 193 condensing boiler manufacturers based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to condensing boiler manufacturers: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	BAXI	Indirect evidence	Warwick, United KingdomHQ checked Sep 16, 2026	1,001-5,000	850 contacts →
	Indirect evidence “We're leading the energy transition to zero carbon, by offering complete residential and commercial heating and hot water solutions.” Source: RevenueBase Database · checked Sep 16, 2026
2	Ideal Heating	Strong evidence	Hull, United KingdomHQ checked Sep 16, 2026	501-1,000	286 contacts →
	Strong evidence “The UK’s leading heating manufacturer, providing reliable, sustainable warmth through boilers, heat pumps and controls Rated Excellent on Trustpilot Award-winning Keeping Homes…” Source: RevenueBase Database · checked Sep 16, 2026
3	Dimplex UK	Indirect evidence	Southampton, United KingdomHQ checked Sep 16, 2026	501-1,000	201 contacts →
	Indirect evidence “For over 75 years, Dimplex has been the trusted name for electric heating.” Source: RevenueBase Database · checked Sep 16, 2026
4	Vaillant UK	Indirect evidence	Belper, United KingdomHQ checked Sep 16, 2026	501-1,000	179 contacts →
	Indirect evidence “What does it take to deliver confidence at every stage of the heating journey?” Source: RevenueBase Database · checked Sep 16, 2026
5	Grant Engineering UK LTD	Partial evidence	Swindon, United KingdomHQ checked Sep 16, 2026	51-200	115 contacts →
	Partial evidence “We are a leading supplier of sustainable heating systems, including HVO boilers, air source heat pumps, solar thermal, hot water storage cylinders, aluminium radiators and…” Source: RevenueBase Database · checked Sep 16, 2026
6	Byworth Boilers Limited	Partial evidence	Keighley, United KingdomHQ checked Sep 16, 2026	51-200	96 contacts →
	Partial evidence “Your industrial boiler is at the heart of your operations.” Source: RevenueBase Database · checked Sep 16, 2026
7	Intergas Heating LTD	Strong evidence	Kidderminster, United KingdomHQ checked Sep 16, 2026	201-500	61 contacts →
	Strong evidence “We’re Dutch, we manufacture ultra-efficient domestic boilers and we want to make the world a better place for all of us.” Source: RevenueBase Database · checked Sep 16, 2026
8	Dunphy Combustion Limited	Strong evidence	Rochdale, United KingdomHQ checked Sep 16, 2026	51-200	53 contacts →
	Strong evidence “Dunphy Combustion Ltd design, manufacture, install and maintain a range of combustion equipment, digital control solutions and turnkey prefabricated, packaged boiler houses.” Source: RevenueBase Database · checked Sep 16, 2026
9	Hamworthy Heating LTD	Partial evidence	Hull, United KingdomHQ checked Sep 16, 2026	51-200	45 contacts →
	Partial evidence “Hamworthy Heating is a British manufacturer and supplier of commercial heating and hot water products.” Source: RevenueBase Database · checked Sep 16, 2026
10	Vokera By Riello	Indirect evidence	Hertfordshire, United KingdomHQ checked Sep 16, 2026	11-50	45 contacts →
	Indirect evidence “For over 40 years, Vokèra has been a trusted name in home heating across the UK and Ireland, delivering reliable, energy efficient solutions for domestic and light commercial…” Source: RevenueBase Database · checked Sep 16, 2026
11	Lochinvar, UK	Strong evidence	Banbury, United KingdomHQ checked Sep 16, 2026	11-50	40 contacts →
	Strong evidence “Lochinvar designs, manufactures and distributes a comprehensive range of high efficiency gas fired water heaters and boilers for commercial and industrial applications.” Source: RevenueBase Database · checked Sep 16, 2026
12	Smith's EP UK	Indirect evidence	Chelmsford, United KingdomHQ checked Sep 16, 2026	51-200	39 contacts →
	Indirect evidence “Founded in 1991, Smith’s EP UK has grown organically to become the UK’s leading supplier of hydronic fan convector products, providing versatile, energy efficient heating…” Source: RevenueBase Database · checked Sep 16, 2026
13	Warmflow Engineering Co. Limited	Indirect evidence	Lisburn, United KingdomHQ checked Sep 16, 2026	51-200	38 contacts →
	Indirect evidence “Warmflow specialise in design, manufacturing, fabrication, sub assembly and kitting solutions.” Source: RevenueBase Database · checked Sep 16, 2026
14	Fulton Boiler Works GB Limited	Strong evidence	Bristol, United KingdomHQ checked Sep 16, 2026	51-200	38 contacts →
	Strong evidence “Fulton Ltd specialises in the design and manufacture of steam, hot water, thermal fluid boilers, packaged plant rooms and skid-mounted systems for industrial, commercial and…” Source: RevenueBase Database · checked Sep 16, 2026
15	Atag Heating Technology UK Limited	Indirect evidence	Dunfermline, United KingdomHQ checked Sep 16, 2026	51-200	31 contacts →
	Indirect evidence “BUILT TO LAST ATAG truly is a unique company.” Source: RevenueBase Database · checked Sep 16, 2026
16	Johnson & Starley LTD	Indirect evidence	Northampton, United KingdomHQ checked Sep 16, 2026	51-200	26 contacts →
	Indirect evidence “As a market leader in providing energy efficient heating and ventilation solutions, Johnson & Starley has an impressive portfolio of products.” Source: RevenueBase Database · checked Sep 16, 2026
17	Strebel UK	Indirect evidence	Farnborough, United KingdomHQ checked Sep 16, 2026	11-50	25 contacts →
	Indirect evidence “Strebel is one of Europe's leading suppliers of commercial heating and hot water solutions.” Source: RevenueBase Database · checked Sep 16, 2026
18	Nerg LTD	Indirect evidence	Lincoln, United KingdomHQ checked Sep 16, 2026	11-50	21 contacts →
	Indirect evidence “We are a Midlands based business, that recommends and installs the right equipment to improves your business's profitability and carbon usage.” Source: RevenueBase Database · checked Sep 16, 2026
19	Thermosphere	Indirect evidence	Marden, United KingdomHQ checked Sep 16, 2026	11-50	18 contacts →
	Indirect evidence “The race to reduce our carbon emissions is on and that means we need to change how we heat homes.” Source: RevenueBase Database · checked Sep 16, 2026
20	Clever Energy Boilers	Partial evidence	Keighley, United KingdomHQ checked Sep 16, 2026	11-50	13 contacts →
	Partial evidence “CLEVER ENERGY BOILERS is part of the Green Deal Factory.” Source: RevenueBase Database · checked Sep 16, 2026
21	Electric Heating Company	Indirect evidence	Blantyre, United KingdomHQ checked Sep 16, 2026	11-50	12 contacts →
	Indirect evidence “The Electric Heating Company have developed their product portfolio to accommodate almost any Central Heating and Hot Water requirement.” Source: RevenueBase Database · checked Sep 16, 2026
22	Lord Combustion Services LTD	Indirect evidence	Oldbury, United KingdomHQ checked Sep 16, 2026	11-50	12 contacts →
	Indirect evidence “Formed in 1982, Lord Combustion Services specialise in the design, installation, repair and maintenance of sustainable heating and hot water systems, supporting over businesses…” Source: RevenueBase Database · checked Sep 16, 2026
23	Watret & CO LTD	Indirect evidence	St Albans, United KingdomHQ checked Sep 16, 2026	11-50	12 contacts →
	Indirect evidence “Watret & Co Ltd is a commercial heating contractor installing domestic heating systems, commercial projects, housing associations and landlords” Source: RevenueBase Database · checked Sep 16, 2026
24	ACV UK	Indirect evidence	Dalgety Bay, United KingdomHQ checked Sep 16, 2026	11-50	10 contacts →
	Indirect evidence “ACV has been designing, manufacturing and distributing heating and hot water products for commercial and residential heating applications since 1922.” Source: RevenueBase Database · checked Sep 16, 2026
25	Ferroli UK	Indirect evidence	Walton On Trent, United KingdomHQ checked Sep 16, 2026	n/a	10 contacts →
	Indirect evidence “Founded by Dante Ferroli in 1955, with offices in San Bonifacio, near the Italian city of Verona, Ferroli controls a global business with factories in Europe and Asia.” Source: RevenueBase Database · checked Sep 16, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: condensing boiler manufacturers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names condensing boiler manufacturers.
Partial evidence: Its own public description names part of condensing boiler manufacturers, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name condensing boiler manufacturers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 193 condensing boiler manufacturers based in the United Kingdom

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Condensing boiler manufacturers based in the United Kingdom at a glance

As of Sep 16, 2026

23.1%Verified-email coverage

18.1Average contacts per company

1-10Median size (employees)

6.2%Largest-city concentration · London

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

101

11-50

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 193 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among condensing boiler manufacturers, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United Kingdom whose own description of what they do matches “condensing boiler manufacturers”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names condensing boiler manufacturers), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among condensing boiler manufacturers, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 807 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 16, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names condensing boiler manufacturers, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many condensing boiler manufacturers are there based in the United Kingdom?

RevenueBase identified 193 condensing boiler manufacturers headquartered in the United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

BAXI, headquartered in Warwick, tops this list with the largest team on record.

Which city has the most condensing boiler manufacturers?

London leads with 12 headquartered companies, followed by Hull (4) and Leeds (4).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 807 verified decision-maker contacts tracked across these 193 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 16, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.