ECO4 Installers Near You: TrustMark, Gas Safe and What Never to Pay Upfront
ApplyFreeBoiler Team
Apply Free Boiler is a private eligibility and application service. We are not the UK Government, Ofgem, your council, an energy supplier, or the installer. See our about page and editorial policy.
Early disclosure
- Short answer: who can install under ECO4?
- What makes an ECO4 installer legitimate
- Which accreditation applies to which measure
- How to check TrustMark, Gas Safe and MCS yourself
- What the ECO4 install journey looks like
- What you should never pay upfront
- How Apply Free Boiler fits in (we are not the government or installer)
- ECO4 installer FAQs
ECO4 measures must be installed by businesses that meet the scheme's installer requirements — in practice TrustMark-registered installers working to PAS 2035/2030, plus Gas Safe for any gas boiler work and MCS for heat pumps or solar (check current Ofgem guidance). You can check all of these yourself in minutes on the official registers. Apply Free Boiler is a private UK eligibility and application service — not the government, Ofgem, a council, an energy supplier, or the installer.
Short answer: who can install under ECO4?
ECO4 measures must be installed by businesses that meet the scheme's installer requirements. In practice that means TrustMark-registered installers working to PAS 2035/2030, plus Gas Safe for any gas boiler work and MCS for heat pumps or solar PV where those measures apply (verify live Ofgem ECO4 guidance ). You can check registrations yourself in minutes — you do not need to trust a logo on a website alone.
Apply Free Boiler is not the government and not the installer. We help households check eligibility and progress applications where a route may exist.
Ready to start? Use accurate household and property details — a survey later decides measures, not marketing copy.
What makes an ECO4 installer legitimate
ECO4 is funded by obligated energy suppliers; installers deliver measures under that scheme and must meet its quality rules. See our British Gas vs ECO4 guide and Octopus ECO4 explained for one-line context: suppliers fund ECO4 and work with installers; Apply Free Boiler is not a supplier.
Legitimacy means the right registrations for the measure being fitted, a proper retrofit assessment or survey, and clear paperwork — not a slick website, borrowed "approved" logos, or a caller claiming to be "the government scheme."
Installer suspensions and enforcement do happen under scheme quality rules, which is why checking TrustMark, Gas Safe and MCS yourself matters. We do not name firms, rank installers, or claim any "AFB-approved" directory.
Which accreditation applies to which measure
Requirements can change — confirm live scheme rules. This table is a homeowner checklist, not legal advice.
| Measure (examples) | What to look for |
|---|---|
| Any ECO4 measure | TrustMark registration (scheme quality mark for ECO / government-endorsed work) |
| Gas boiler replacement / first-time gas central heating — free boiler grant guide | TrustMark and Gas Safe Register (legal requirement for gas work in Great Britain) |
| Air source heat pump — heat pump grant guide | TrustMark and MCS certification |
| Solar PV — solar panels grant guide | TrustMark and MCS certification |
| Loft insulation — loft insulation grants | TrustMark; PAS 2030 installer for the measure; scheme guarantees as applicable (check current scheme rules) |
| Cavity wall insulation — cavity wall insulation grants | TrustMark; PAS 2030 installer for the measure; guarantees per scheme (check current scheme rules) |
| Internal wall insulation (IWI) — IWI grant guide | TrustMark; PAS 2030 installer for the measure; guarantees per scheme (check current scheme rules) |
| External wall insulation (EWI) — external wall insulation grants | TrustMark; PAS 2030 installer for the measure; guarantees per scheme (check current scheme rules) |
| Whole-house retrofit | PAS 2035 retrofit assessment + retrofit coordinator |
How to check TrustMark, Gas Safe and MCS yourself
- Get the exact registered company name (and Gas Safe licence number for the engineer) in writing before anyone visits.
- Search TrustMark's find-a-tradesperson register ; confirm the trade or measure is listed and status is current.
- Search the Gas Safe Register by business or engineer licence number; check the engineer's card on the day (photo, licence number, gas categories).
- For heat pumps or solar, search the MCS installer database .
- If any lookup fails or names do not match → stop and ask questions before sharing documents or bank details.
For a broader scam checklist (without repeating every red flag here), see is the free boiler grant a scam?
What the ECO4 install journey looks like
Timelines vary by area and installer capacity. These steps help you spot when a fee request does not belong in the process.
- Eligibility check (household + property) — soft eligibility check; eligibility ≠ guaranteed funding.
- Application / referral to a funded installer route — apply.
- Retrofit assessment / survey at home (PAS 2035) — the survey decides which measures may be funded.
- Measures agreed and scheduled — in writing where possible before work starts.
- Installation by registered installers for each measure (TrustMark / Gas Safe / MCS as relevant).
- Sign-off, certificates (for example Gas Safe / building-regs notification for boilers; MCS certificate for renewables), guarantees and scheme lodgement where applicable. For a new boiler, you can confirm the notification with our Gas Safe certificate check.
Process overview: how it works. Deadline context: ECO4 ends 31 December 2026.
What you should never pay upfront
Under a fully funded ECO4 measure there is normally no upfront "application", "survey booking", or "grant release" fee to an installer or cold caller. Be cautious of anyone asking for bank details or card payment to "secure" funding. If a top-up is ever proposed for extra work, it should be explained in writing after the survey and before work starts.
For the full red-flag checklist, see the scam and trust guide linked in the check-yourself section above. Confused by "interest-free" boiler ads? See interest-free boiler vs ECO4 free grant.
How Apply Free Boiler fits in (we are not the government or installer)
Apply Free Boiler is a private UK eligibility and application service for ECO4 and related pathways. We check eligibility and paperwork and route you toward appropriately registered (TrustMark / Gas Safe / MCS as relevant) installers where a route may exist.
We are not the government, not Ofgem, not a council, not an energy supplier, and not the installer. Run the same register checks on any installer you meet — including anyone you reach through us. Eligibility does not guarantee funding or a specific measure; a survey decides outcomes.
Start with accurate details. We will not ask you to skip TrustMark or Gas Safe checks.
ECO4 installer FAQs
Next step
Searching for ECO4 installers? Check TrustMark, Gas Safe and MCS yourself, know where fees should not appear, then start an application if you want private help — not government or installer services from us.