The free Find & Fix audit, and whether you qualify
If your external wall insulation was installed under ECO4 or the Great British Insulation Scheme, TrustMark offers a free audit, and any faults it finds should be put right without you paying. This page explains how that works, who pays, and what to do if it does not apply to you. We are not part of TrustMark or the scheme.
Which route applies to you
These are genuinely different situations. Starting in the wrong place wastes months.
External wall insulation under ECO4 or GBIS
Every household that had external wall insulation under these schemes is being offered a free audit by TrustMark. If faults are found, you should not be asked to pay for the repair.
Go to TrustMark. Not to us.
Internal wall insulation under ECO4 or GBIS
Government guidance is that no action should be required unless you have concerns. Audits found major issues in fewer internal wall installations than external.
Only contact Ofgem if you have concerns.
Anything outside those schemes
Spray foam, work you paid for privately, or a property with no scheme guarantee behind it. Check any guarantee first — cavity wall insulation often has one from CIGA.
This is where we can help.
Who actually pays for the repair
According to the National Audit Office and the government, responsibility runs in this order:
- 1The installer who did the work.
- 2The 25-year guarantee on the work, if the installer has stopped trading or will not fix it. Guarantees cover repairs up to £20,000, or up to £25,000 where the guarantee is from the Installation Assurance Authority (raised in June 2026).
- 3The National Energy Foundation, for some homes where the installer has gone out of business and the guarantee was cancelled, fraudulent or missing. Ask TrustMark or Ofgem's ECO helpline whether this applies.
The government's position is that households should not be asked to pay for these repairs, including where the installer has gone out of business. The guarantees do not cover other losses, such as damaged belongings or ill health — for those, get independent advice, for example from Citizens Advice.
How to book the free audit
Contact TrustMark directly
TrustMark runs the government's Find & Fix programme. The audit is free and you do not need to go through anyone else — including us. TrustMark says it may take several months to contact every household.
Lines are open Monday to Friday, 9am to 5pm.
Have your Ofgem letter to hand if you can
Ofgem wrote to around 60,000 households with external or internal wall insulation by February 2025. That letter contains a UMRN — a Unique Measure Reference Number — which identifies your specific installation and saves a lot of "we have no record of you". It is worth digging out, but do not let a lost letter stop you calling. TrustMark advises that anyone contacting you about the audit should be able to quote it.
If you have already had a home check
Government guidance is that if you have had a home check since January 2025, no further action is required.
If you had internal wall insulation
The position is different. Government guidance is that no action should be required for internal wall insulation unless you have concerns. Households are not all audited; concerns raised with Ofgem are assessed and may lead to an audit.
If you do have concerns, your route is Ofgem, not TrustMark: 0808 169 4447 (Monday to Friday, 9.30am to 4.30pm) or ECOhelp@ofgem.gov.uk.
If somebody rings you out of the blue
Households affected by a bad installation are frequently targeted a second time, by callers offering to handle a "claim" for a fee. The free audit is booked by you, with TrustMark, at no cost. Nobody needs to arrange it on your behalf and nobody should be charging you for access to it.
If a caller claims to be from the scheme, ask them for your Unique Measure Reference Number. TrustMark advises not letting anyone in who cannot give it.
If no free route covers you
Spray foam, older cavity wall fill, private work, or an urgent problem you do not want to queue for.
If no free route covers your home, we can introduce you to a specialist through Better Home Hub. Sending an enquiry is free; the specialist may pay Better Home Hub a fee, and any survey or work is agreed and paid for between you and them.
Sources
- TrustMark — free Find & Fix audit offer
- gov.uk — what to do if you have poor quality wall insulation
- National Audit Office — Energy efficiency installations under the Energy Company Obligation (HC 1334, 14 October 2025)
- Public Accounts Committee — Faulty energy efficiency installations (HC 1229, 23 January 2026)
- DESNZ — Greater protections to restore families' trust in home upgrades (17 June 2026)
- Ofgem — ECO complaints process
Last reviewed 13 September 2026.