Company lists · Data refreshed September 2026

Top 25 Geothermal energy installation companies based in the United Kingdom

Name: Geothermal energy installation companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 15, 2026 512 companies tracked

RevenueBase identified 512 geothermal energy installation companies headquartered in the United Kingdom as of September 2026 and tracks 3,864 professional contacts across them, including 1,187 with verified work emails. London is the largest hub.

This list covers geothermal energy installation companies 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 15, 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 15, 2026 86% judged on-target in blind review

512Companies

3,864Contacts tracked

1,187Verified emails

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The 25 largest geothermal energy installation companies based in the United Kingdom

Ranked by team size

Top 25 of 512 geothermal energy installation companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 15, 2026. RevenueBase Smart Search rates how each company's information relates to geothermal energy installation companies: 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	Partial evidence	Warwick, United KingdomHQ checked Sep 15, 2026	1,001-5,000	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 15, 2026
2	BOXT	Partial evidence	Leeds, United KingdomHQ checked Sep 15, 2026	51-200	116 contacts →
	Partial evidence “We started out as a trailblazing boiler installation company in 2017 – the first to offer everything effortlessly online.” Source: RevenueBase Database · checked Sep 15, 2026
3	Glow Green	Indirect evidence	Bournemouth, United KingdomHQ checked Sep 15, 2026	51-200	110 contacts →
	Indirect 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 15, 2026
4	Star Energy Group PLC	Partial evidence	Sudbrooke, United KingdomHQ checked Sep 15, 2026	51-200	83 contacts →
	Partial evidence “Star Energy Group plc is a British energy business.” Source: RevenueBase Database · checked Sep 15, 2026
5	Nu-Heat Underfloor Heating & Renewables	Partial evidence	Honiton, United KingdomHQ checked Sep 15, 2026	51-200	70 contacts →
	Partial evidence “As the UK's largest supplier of warm water underfloor heating and integrated renewables, Nu‑Heat delivers fully designed, energy efficient systems to installers, housebuilders…” Source: RevenueBase Database · checked Sep 15, 2026
6	Rendesco	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	60 contacts →
	Partial evidence “Rendesco is the UK’s leading clean energy tech developer and operator, focusing on the electrification of heat using heat pumps and heat networks to decarbonise Britain’s…” Source: RevenueBase Database · checked Sep 15, 2026
7	Cooltherm	Indirect evidence	Bridgeyate, United KingdomHQ checked Sep 15, 2026	51-200	54 contacts →
	Indirect evidence “With over 30 years of expertise, Cooltherm delivers sustainable HVAC solutions across healthcare, education, construction, data centres, factories & manufacturing, and warehouse &…” Source: RevenueBase Database · checked Sep 15, 2026
8	Solmatix Renewables LTD	Partial evidence	Dundrod Rd, United KingdomHQ checked Sep 15, 2026	11-50	41 contacts →
	Partial evidence “Founded in 2008, Solmatix is one of the UK's and Ireland's leading renewable energy specialists, delivering innovative, high-quality energy solutions for commercial, industrial…” Source: RevenueBase Database · checked Sep 15, 2026
9	B-Engineering Group Certified B Corp	Indirect evidence	Warrington, United KingdomHQ checked Sep 15, 2026	51-200	39 contacts →
	Indirect evidence “We are a purpose driven engineering business, passionate about our people and the environment.” Source: RevenueBase Database · checked Sep 15, 2026
10	Golden Globe Merchants LTD	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	11-50	38 contacts →
	Partial evidence “At Golden Globe Merchants, we deliver high-performance, energy-efficient solutions designed to future-proof UK homes.” Source: RevenueBase Database · checked Sep 15, 2026
11	Pure Renewables	Partial evidence	Hull, United KingdomHQ checked Sep 15, 2026	11-50	37 contacts →
	Partial evidence “As commercial and industrial heat pump and solar PV specialists, Pure Renewables are here to help you invest in your energy future.” Source: RevenueBase Database · checked Sep 15, 2026
12	Principal Hvac	Indirect evidence	Belfast, United KingdomHQ checked Sep 15, 2026	51-200	34 contacts →
	Indirect evidence “Principal HVAC are at the leading edge of Heating, Ventilation & Air conditioning systems for commercial and residential property.” Source: RevenueBase Database · checked Sep 15, 2026
13	Oakland AIR Control	Indirect evidence	Worcester, United KingdomHQ checked Sep 15, 2026	11-50	30 contacts →
	Indirect evidence “We are a specialist heating, ventilation, air conditioning (HVAC), heat pump, electrical and BEMS controls engineering solutions business and post ESOS service provider.” Source: RevenueBase Database · checked Sep 15, 2026
14	Stiebel Eltron UK LTD	Indirect evidence	Bromborough, United KingdomHQ checked Sep 15, 2026	11-50	28 contacts →
	Indirect evidence “STIEBEL ELTRON UK is a leading manufacturer of premium heat pumps and renewable heating solutions, electric hot water and room heating and ventilation, supplying high-quality…” Source: RevenueBase Database · checked Sep 15, 2026
15	Geothermal Development Company	Strong evidence	Great Yarmouth, United KingdomHQ checked Sep 15, 2026	11-50	28 contacts →
	Strong evidence “CeraPhi Energy is a leading project development company delivering global geothermal energy solutions at scale.” Source: RevenueBase Database · checked Sep 15, 2026
16	M&n Heating & Plumbing	Indirect evidence	Banbury, United KingdomHQ checked Sep 15, 2026	51-200	26 contacts →
	Indirect evidence “M&N Heating & Plumbing is an independent company based in Bloxham on the edge of Banbury, serving Oxfordshire, Northamptonshire, Buckinghamshire and Warwickshire.” Source: RevenueBase Database · checked Sep 15, 2026
17	Jaga UK	Indirect evidence	Ledbury, United KingdomHQ checked Sep 15, 2026	11-50	24 contacts →
	Indirect evidence “Ensuring a better indoor climate without damaging the outdoor climate.” Source: RevenueBase Database · checked Sep 15, 2026
18	Taranis Engineering LTD	Indirect evidence	Flax Bourton, United KingdomHQ checked Sep 15, 2026	11-50	24 contacts →
	Indirect evidence “Taranis engineering was formed in October 2013 by the former director shareholders of JCW air-conditioning together with Jon Salter, John Lawrence and Alex Bond.” Source: RevenueBase Database · checked Sep 15, 2026
19	Rayotec LTD	Partial evidence	Sunbury On Thames, United KingdomHQ checked Sep 15, 2026	11-50	22 contacts →
	Partial evidence “Rayotec are specialists in renewable energy solutions.” Source: RevenueBase Database · checked Sep 15, 2026
20	Drilcorp	Indirect evidence	Seaham, United KingdomHQ checked Sep 15, 2026	11-50	21 contacts →
	Indirect evidence “Drilcorp was established in 1992 and since then has developed into one of the UK’s top drilling companies.” Source: RevenueBase Database · checked Sep 15, 2026
21	Link365 Mechanical, Electrical & Renewable Energy Solutions	Partial evidence	Essex, United KingdomHQ checked Sep 15, 2026	51-200	21 contacts →
	Partial evidence “We provide Complete Mechanical, Electrical and Renewable Energy Solutions.” Source: RevenueBase Database · checked Sep 15, 2026
22	Macbrookgas LTD	Indirect evidence	Banham, United KingdomHQ checked Sep 15, 2026	51-200	19 contacts →
	Indirect evidence “MACBROOKGAS LTD is a heating and Insulation company based out of United Kingdom.” Source: RevenueBase Database · checked Sep 15, 2026
23	R.G.Evans Plumbing And Heating	Indirect evidence	Bourne End, United KingdomHQ checked Sep 15, 2026	51-200	18 contacts →
	Indirect evidence “R.G.Evans Plumbing and Heating is part of the Evans Group, a family run business operating throughout South East England since 1948.” Source: RevenueBase Database · checked Sep 15, 2026
24	HEX Energy LTD	Partial evidence	Nuneaton, United KingdomHQ checked Sep 15, 2026	11-50	17 contacts →
	Partial evidence “Our aim is to provide renewable energy systems for properties that would clearly benefit from them.” Source: RevenueBase Database · checked Sep 15, 2026
25	Home & Industrial Heating Services Limited	Indirect evidence	Eastleigh, United KingdomHQ checked Sep 15, 2026	11-50	17 contacts →
	Indirect evidence “H&I (Home & Industrial) Heating was established in 1972 as a sole trader/partnership for the Heating Industry.” Source: RevenueBase Database · checked Sep 15, 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: geothermal energy installation companies. 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 energy installation companies.
Partial evidence: Its own public description names part of geothermal energy installation companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name geothermal energy installation companies. 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 512 geothermal energy installation companies based in the United Kingdom

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Geothermal energy installation companies based in the United Kingdom at a glance

As of Sep 15, 2026

30.7%Verified-email coverage

7.5Average contacts per company

1-10Median size (employees)

7.0%Largest-city concentration · London

Sep 15, 2026Page data refreshed

Companies by employee count

1-10

290

11-50

177

51-200

201-500

1,001-5,000

10001+

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 512 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 geothermal energy installation companies, 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 “geothermal energy installation companies”. 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 energy installation companies), 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 energy installation companies, 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, 1,187 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 15, 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 energy installation companies by metro

Geothermal energy installation companies in London36

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 energy installation companies, 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 energy installation companies are there based in the United Kingdom?

RevenueBase identified 512 geothermal energy installation companies 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 geothermal energy installation companies?

London leads with 36 headquartered companies, followed by Glasgow (9) and Bristol (8).

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 1,187 verified decision-maker contacts tracked across these 512 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 15, 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.