Company lists · Data refreshed September 2026
Top 25 Geothermal heating installers worldwide
RevenueBase identified 5,653 geothermal heating installers worldwide as of September 2026 and tracks 29,888 professional contacts across them, including 8,155 with verified work emails. The United Kingdom is the largest market and London the largest hub.
This list covers geothermal heating installers worldwide, 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 19, 2026. Country and city lists for geothermal heating installers follow the table.
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.
The 25 largest geothermal heating installers worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 850 contacts → | ||||
Partial 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 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 781 contacts → | ||||
Indirect evidence “Sinds het ontstaan in 1947 is Feenstra marktleider in installatietechniek met een nationale dekking.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 294 contacts → | ||||
Indirect evidence “Following Rinnai's international origins dating back more than 100 years, Rinnai Australia was established 50 years ago and since then has been providing Australians with the best…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 224 contacts → | ||||
Indirect evidence “WaterFurnace International, Inc.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 211 contacts → | ||||
Indirect evidence “De energietransitie is één van de grootste maatschappelijke opgaven, maar wij begrijpen dat jouw wooncomfort net zo belangrijk is.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 186 contacts → | ||||
Indirect evidence “Bonarius Bedrijven De naam Bonarius was lange tijd synoniem voor de aanleg en het onderhoud van cv-installaties.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 162 contacts → | ||||
Indirect evidence “Mit Premium-Photovoltaikanlagen und Wärmepumpen im Komplettpaket erleichtern wir seit 2010 Privat- und Gewerbekunden bundesweit den Umstieg auf eine unabhängige, nachhaltige…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 149 contacts → | ||||
Indirect evidence “Eteck levert duurzame energie in de vorm van koude en warmte.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 143 contacts → | ||||
Partial evidence “The UK’s heating system is stuck in the past, costing people and the planet too much.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 136 contacts → | ||||
Indirect evidence “Enter ist ein bundesweit tätiger Anbieter von Wärmepumpen, Solaranlagen (Photovoltaik) mit Stromspeicher, Wallboxen und Energiemanagement-Systemen für Eigenheimbesitzer in…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 136 contacts → | ||||
Partial evidence “As an established heating company based in Kent, Swale Heating are proud to offer expert guidance in choosing the best heating and boiler systems & products available today.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 132 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 128 contacts → | ||||
Partial evidence “ABOUT http://iceland-drilling.com/ Iceland Drilling Ltd is a leading high technical company in the field of high temperature geothermal drilling and has many decades of experience…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 125 contacts → | ||||
Indirect evidence “We are Bring Energy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 123 contacts → | ||||
Indirect evidence “Polaron has defined excellence in Canada’s renewable energy sector since 2013, with proven staying power amid a fast paced industry and a vast portfolio of over installations.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 118 contacts → | ||||
Strong evidence “Dandelion Energy is the nation’s leading residential geothermal provider, on a mission to make the world’s most efficient heating and cooling technology accessible to everyone.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 116 contacts → | ||||
Indirect evidence “We started out as a trailblazing boiler installation company in 2017 – the first to offer everything effortlessly online.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 114 contacts → | ||||
Indirect evidence “Heat Merchants Group trading as Heat Merchants, Bathroom Merchants, and Tubs & Tiles, is part of Wolseley group since 2022.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 112 contacts → | ||||
Partial evidence “BRÖTJE efficient heating system technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 112 contacts → | ||||
Indirect evidence “As renewable energy technology experts, we have the knowledge and skills to help commercial clients switch to a greener, lower cost and more independent energy source.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 110 contacts → | ||||
Indirect evidence “At ENCON, we take care of people.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 110 contacts → | ||||
Partial evidence “Glow Green is one of the UK's leading installers of Solar Panels, Battery Storage, Heat Pumps, Boilers, AC Units, & EV Chargers.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 108 contacts → | ||||
Indirect evidence “Brightcore Energy is a leading renewable energy solutions provider serving commercial, institutional, and government clients.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 101 contacts → | ||||
Partial evidence “Haliburton Geothermal has been established to provide economical and environmental choices pertaining to geothermal in Haliburton Country.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 100 contacts → | ||||
Indirect evidence “Mit innovativer Technik zur Übergabe und Verteilung von Wärme auf der entscheidenden „letzten Meile“ vereinfacht und beschleunigt PEWO die Integration regenerativer Energiequellen.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
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: geothermal heating installers. 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 geothermal heating installers.
- Partial evidence
- Its own public description names part of geothermal heating installers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name geothermal heating installers. 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 5,653 geothermal heating installers worldwide
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Geothermal heating installers worldwide at a glance
As of Sep 19, 2026Companies by employee count
Email recency is reported on each country list linked below.
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 geothermal heating installers, 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.
- Coverage
- Every country. Country and city lists for geothermal heating installers are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “geothermal heating installers”. 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 geothermal heating installers), 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 geothermal heating installers, and records with no verified work email.
- 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, 8,155 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 19, 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.
Geothermal heating installers by location
17 lists · largest firstEvery Geothermal heating installers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Geothermal heating installers based in the United Kingdom798
- Geothermal heating installers based in France710
- Geothermal heating installers based in Germany542
- Geothermal heating installers based in the United States514
- Geothermal heating installers based in the Netherlands409
- Geothermal heating installers based in Spain280
- Geothermal heating installers based in Italy264
- Geothermal heating installers based in Belgium207
- Geothermal heating installers based in Poland174
- Geothermal heating installers based in Switzerland128
- Geothermal heating installers based in Canada122
- Geothermal heating installers based in Australia76
- Geothermal heating installers based in Austria63
- Geothermal heating installers based in Ireland63
- Geothermal heating installers based in Sweden52
- Geothermal heating installers based in Finland51
- Geothermal heating installers based in Denmark40
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 geothermal heating installers, 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 geothermal heating installers are there worldwide?
RevenueBase identified 5,653 geothermal heating installers worldwide 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 country has the most geothermal heating installers?
The United Kingdom leads with 798 companies, followed by France (710) and Germany (542). Every geothermal heating installers list by country and city is linked on this page.
Which city has the most geothermal heating installers?
London leads with 49 headquartered companies, followed by Madrid (26) and Berlin (24).
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 8,155 verified decision-maker contacts tracked across these 5,653 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 19, 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.