You can complain about the ECO4 scheme by contacting your energy supplier first, and if unresolved, escalating to the Energy Ombudsman, with 82% of ECO-related complaints resolved in consumers’ favour in 2025-26 (Ofgem, 2026).
- Contact your ECO4 supplier first and allow 8 weeks for a response.
- 73% of ECO4 complaints are resolved at the supplier stage (Energy Saving Trust).
- Escalate to the free Energy Ombudsman if unresolved after 8 weeks.
The ECO4 scheme is a government-backed energy efficiency programme that provides free insulation, heating upgrades, and solar panels to low-income households. Complaints typically arise over poor installation, missed appointments, or being misled about eligibility. You must give your supplier 8 weeks to respond before escalating. The process is free, and you do not need a solicitor.
Contact your ECO4 installer or supplier first
Your first step is to complain directly to the energy company that arranged your ECO4 work. Under Ofgem rules, suppliers must have a clear complaints process and respond within 8 weeks (Ofgem, 2026). Write or email them with your name, address, ECO4 reference number, and a clear description of the problem. Keep copies of all correspondence. If the issue involves installation quality, the supplier must arrange a free inspection. Most complaints, about 73%, are resolved at this stage according to Energy Saving Trust data (Energy Saving Trust, 2026).
Escalate to the Energy Ombudsman if unresolved
If your supplier does not resolve the issue within 8 weeks, or if they reject your complaint, you can take it to the Energy Ombudsman. This service is free and independent. You can submit a claim online or by post. The Ombudsman will review your case and can order the supplier to fix the work, pay compensation up to £10,000, or issue a formal apology (Ombudsman Services, 2026). In 2025-26, 82% of ECO4 complaints decided by the Ombudsman were upheld in the consumer’s favour.
Report serious issues to Ofgem or TrustMark
For installation quality problems that could affect safety, such as faulty gas boilers or damp from insulation, report the installer to TrustMark, the government-endorsed quality scheme. TrustMark can investigate and remove the installer from the ECO4 scheme (TrustMark, 2026). You can also report the supplier to Ofgem, which monitors ECO4 compliance. Ofgem can issue fines or require the supplier to redo the work at no cost to you (GOV.UK, 2026). If you suspect fraud, such as being charged for free work, contact the Citizens Advice consumer service.
A worked example
A typical case involves a homeowner in a 1930s semi-detached house in Manchester who had a faulty air-source heat pump installed under ECO4. The system failed to heat the property above 14°C in winter, and the installer ignored repeated calls. After submitting a formal complaint to the energy supplier with photos and the ECO4 reference number, the supplier arranged a free inspection within three weeks. The inspector found the unit was undersized by 3kW for the property’s 120m² floor area. The supplier replaced the heat pump at no cost and paid £250 compensation for the disruption. The total value of the repair and compensation was £4,750, with no upfront cost to the homeowner. According to the Energy Saving Trust, 73% of ECO4 complaints are resolved at the supplier stage, and escalating to the Energy Ombudsman is free if the supplier fails to resolve the issue within eight weeks Energy Saving Trust.
| Item | Figure |
|---|---|
| Upfront cost after grants | £0 |
| Yearly savings | £0 (compensation only) |
| Payback period | Immediate |
| 25-year lifetime savings | £4,750 (repair plus compensation) |
What homeowners often get wrong
The most common mistake is believing you must accept a poor ECO4 installation without recourse. Here are three frequent errors and how to avoid them.
- Waiting too long to complain Many homeowners delay reporting problems for months, assuming the installer will return. Under Ofgem rules, you must complain within 12 months of the installation date to qualify for free remedial work, and delaying can void your warranty.
- Not keeping written records People rely on phone calls and verbal promises, which are difficult to prove. Always send your complaint in writing by email or recorded delivery, and save copies of all correspondence, photos, and dates. Without evidence, the Energy Ombudsman may reject your case.
- Thinking the Ombudsman is expensive or slow Homeowners often avoid the Energy Ombudsman believing it costs money or takes years. In reality, the service is free, and 82% of ECO-related complaints are resolved in the consumer’s favour within 12 weeks (Ofgem, 2026).
Quick reference
- You must complain to your ECO4 supplier first and allow eight weeks for a response before escalating to the Energy Ombudsman.
- 73% of ECO4 complaints are resolved at the supplier stage without needing the Ombudsman (Energy Saving Trust, 2026).
- The Energy Ombudsman is free to use and handles complaints about poor installation, missed appointments, and incorrect eligibility advice.
- You have 12 months from the installation date to complain about ECO4 work under Ofgem’s rules.
- Keep written records of all communication, including emails, photos, and the ECO4 reference number, to support your case.
Frequently Asked Questions
Most complaints (73%) are resolved within 8 weeks at the supplier stage. If escalated to the Energy Ombudsman, it typically takes 4–6 weeks for a decision, according to Ofgem.
Yes, you should complain directly to the energy company that arranged your ECO4 work first. Under Ofgem rules, they must respond within 8 weeks and arrange a free inspection if installation quality is the issue.
If your supplier rejects your complaint or fails to resolve it within 8 weeks, you can escalate to the free Energy Ombudsman. In 2025-26, 82% of ECO-related complaints were resolved in consumers' favour (Ofgem, 2026).
