TrustMark - September 2026

The Government’s ECO4 scheme allows low-income households and people in receipt of benefits to get huge discounts on measures to make their homes more energy efficient. Every single installer who carried out the work was on the “TrustMark” register, showing that they were all approved by this government-endorsed scheme, that was made available to over 300,000 homeowners.

Andrew and Fiona had loft and external wall insulation installed on their home in Nuneaton, which was completed in February 2025. However, the insulation installed on the outside of their house started causing issues inside. They noticed damp coming into a bedroom and cracks began appearing along the walls that worsened over time. They paid for a chartered surveyor to come out, who advised that “it needs to be stripped off back to the brick.” They arranged for the original company to come back to try and fix the problem, but when TrustMark conducted an audit on the remedial work, it ruled it non-compliant. Andrew and Fiona are devastated at the state their home was left in. When they requested help, they were told the company responsible had lost its TrustMark approval, and because of that it could no longer help fix the damage, leaving them facing a costly repair bill.

TrustMark will only help to rectify issues if the company is still on its list of approved installers. It publishes a list of companies that have been suspended, but the company that carried out Fiona and Andrew’s work isn’t on the list. Watchdog discovered that the list doesn’t include installers who have been expelled permanently.

Richard and Vicky picked a TrustMark-approved company to help make their home more efficient and noticed problems soon after. When they reached out for help, the original company subcontracted some of the installation to another approved company, and when the couple complained about the problems, TrustMark carried out an audit finding several issues. But Richard and Vicky were told that both companies had since lost their TrustMark seal of approval, and it said, it could no longer help.

When we wrote to TrustMark it told us it finds it wholly unacceptable that consumers have been left in these situations, and that it is working urgently with government, certification bodies and guarantee providers to help fix them. It told us that the examples Watchdog brought to its attention underline the need for change and reform to the current system so that protections for consumers are stronger and easier to understand and access. We were told that, under the Find & Fix programme, TrustMark is a single point of contact to support affected homeowners through the process and find solutions to enable them to live in warmer and more comfortable homes.

TrustMark told us that, if anyone who had external wall insulation installed under ECO4 is experiencing issues, they should contact TrustMark on 0333 555 1234 and select option 1or at [email protected] to book a free audit.

We also wrote to the Department for Energy Security and Net Zero which told us it inherited the failing ECO4 scheme, which it ended after it clearly let families down. We were told that over 9,000 households have already been contacted by TrustMark, and it is helping every household affected to access an audit as quickly as possible. We were told that the government’s Warm Homes Plan will overhaul the system to protect consumers and ensure failings are not repeated.