Complaining About Poor ECO4 Installation Work: Your Rights

ECO4 complaint poor workmanship cases have surged in recent years as the scale of government-funded installation work has expanded. Reports of damp caused by incorrectly fitted insulation, heating systems that fail within months, and shoddy finishing work have left thousands of homeowners wondering where to turn. If you have received poor quality work through the ECO4 scheme, you have clear rights and multiple routes to get the problem fixed at no cost to you.

How to Complain About Poor ECO4 Installation Work

If you have received a poor-quality ECO4 installation — such as badly fitted insulation, a leaking boiler or incomplete work — follow these steps to get the problem resolved:

1. Document the problem with dated photographs, videos and written notes describing what is wrong
2. Contact the installer directly and request they return to fix the work under their warranty
3. If the installer does not respond within 14 days, complain to your energy supplier who funded the ECO4 measure
4. Report the installer to TrustMark, who can investigate and remove their accreditation if standards are not met
5. Escalate to Ofgem if your energy supplier fails to resolve the complaint, as suppliers are responsible for the quality of ECO4 work
6. Contact Citizens Advice on 0808 223 1133 for free support navigating the complaints process

All ECO4 installations must meet PAS 2030 standards and be registered with TrustMark. This means the work carries a minimum 25-year guarantee for insulation and 2 years for heating systems. If the original installer has gone out of business, TrustMark’s guarantee protection scheme may cover the cost of remedial work.

The Scale of ECO4 Quality Problems

The Energy Company Obligation has funded millions of energy efficiency measures since 2013, but quality control has been a persistent issue. In 2024, Ofgem’s own monitoring found that approximately 15% of ECO4 installations had quality defects ranging from minor finishing issues to serious structural and moisture problems.

The most commonly reported problems include:

• Solid wall insulation failures: Cracking, delamination, water ingress through poor detailing around windows and doors, and missing ventilation causing condensation and mould
• Cavity wall insulation problems: Incomplete fill, wrong material for exposed walls, moisture bridging leading to damp patches on internal walls
• Loft insulation issues: Blocking of eaves ventilation, insulation piled over electrical cables, and displacement of existing insulation causing cold spots
• Boiler installation defects: Incorrect flue positioning, poor pipework, failure to flush the system properly, and missing safety documentation
• Heat pump problems: Undersized systems, incorrect refrigerant charge, poor placement of outdoor units, and inadequate commissioning

These failures are not inevitable. Well-managed installations by competent, properly supervised contractors produce excellent results. The problems tend to be concentrated among a minority of installers operating at the lower end of the market, often subcontracting work through long chains where quality oversight is weak.

Your Protection: The TrustMark Guarantee

All ECO4 installations must be carried out by TrustMark-registered businesses and lodged on the TrustMark Data Warehouse. This registration provides you with significant protection:

• 25-year guarantee: Every ECO4 installation is backed by a guarantee lasting up to 25 years, covering defective workmanship and materials
• Financial protection: If the original installer goes bust, the guarantee is backed by a financial protection scheme that will fund remediation work by an alternative contractor
• Dispute resolution: TrustMark operates an Alternative Dispute Resolution (ADR) service for complaints that cannot be resolved directly with the installer
• Quality standards: Work must comply with PAS 2030 (installation standards) and PAS 2035 (retrofit assessment and design standards)

The 25-year guarantee is one of the strongest consumer protections available for any home improvement work in the UK. By comparison, a typical private installation guarantee lasts only 2 to 10 years. This guarantee covers the cost of putting right any defect in the installed measure, including any consequential damage to your property caused by the defective work.

Step 1: Complain Directly to the Installer

Your first step should always be to contact the company that carried out the installation work. They have a legal obligation to put right any defective work and most reputable installers will do so promptly.

How to complain effectively:

• Contact the installer in writing (email is fine) so you have a dated record
• Describe the problem clearly, including when you first noticed it
• Include photographs showing the defect
• Reference your installation paperwork, including the TrustMark lodgement reference and any guarantee certificates
• State clearly what you want: a return visit to fix the problem, and compensation for any damage caused
• Give them a reasonable deadline to respond, typically 14 days

If you do not know who the installer was, check your TrustMark lodgement paperwork or contact TrustMark directly on 0333 555 1234. They can look up which company carried out the work on your property.

Step 2: Escalate Through TrustMark Dispute Resolution

If the installer does not respond, refuses to fix the problem, or their remediation work is inadequate, you can escalate through TrustMark’s dispute resolution process.

How TrustMark ADR works:

• Submit a complaint through the TrustMark website or by calling 0333 555 1234
• TrustMark will contact the installer and attempt to mediate a resolution
• If mediation fails, the case is referred to an independent adjudicator
• The adjudicator reviews evidence from both sides and makes a binding decision
• If the decision is in your favour, the installer must carry out remediation within an agreed timeframe

If the installer has ceased trading, TrustMark will arrange for an alternative contractor to carry out the remediation work under the financial protection scheme. The cost is covered by the guarantee, not by you. This protection exists specifically because the government recognised that some installers would inevitably fail, and homeowners should not be left without recourse.

Step 3: Report to Ofgem’s ECO Team

As the regulator of the ECO scheme, Ofgem has enforcement powers over both energy suppliers and installers. If your complaint is not being resolved through TrustMark, or if you believe there are systemic quality problems with a particular installer, you should report the issue to Ofgem.

How to report to Ofgem:

• Email eco@ofgem.gov.uk with details of your complaint
• Include all documentation: installation certificates, photographs of defects, correspondence with the installer and TrustMark
• Describe the timeline of events and the current status of your complaint

Ofgem uses consumer complaints to identify poor-performing installers and can take enforcement action including:

• Requiring the obligated energy supplier (the company that funded the measure through ECO4) to arrange remediation
• Suspending or removing an installer’s ability to carry out ECO4 work
• Investigating the energy supplier’s oversight of their installer supply chain
• Publishing performance data that names underperforming installers

Importantly, the energy supplier that funded the ECO4 measure (such as British Gas, EDF, E.ON or OVO) retains ultimate responsibility for the quality of work carried out under their obligation. If the installer fails to fix the problem, the energy supplier must arrange remediation.

Step 4: Involve Your Local Authority

If the defective work has caused a health hazard in your home, such as damp, mould or a gas safety issue, your local council’s environmental health team can intervene.

Under the Housing Health and Safety Rating System (HHSRS), local authorities have powers to require landlords and, in some circumstances, to assist owner-occupiers with homes that pose health risks. If ECO4 work has made your home less safe or habitable than it was before the installation, this is a serious matter.

For rented properties, your landlord has a legal duty to ensure the home is fit for habitation. If ECO4 work carried out on a rented property has caused problems, the landlord must arrange remediation and cannot pass the cost to you.

Common ECO4 Quality Issues and How They Should Be Fixed

All of these remediation costs should be borne by the installer or the guarantee scheme, not by you. If anyone asks you to pay for fixing defective ECO4 work, refuse and escalate your complaint.

How to Protect Yourself During ECO4 Installation

Prevention is better than cure. If you are about to have ECO4 work carried out, these steps can help you avoid problems:

• Verify TrustMark registration before work begins. Check the installer on the TrustMark website
• Photograph everything before, during and after installation. Take photos of walls, windows, ventilation openings and any areas that will be covered by insulation
• Ask questions about what material will be used, how ventilation will be maintained, and what the installation timeline is
• Insist on seeing the PAS 2035 assessment and improvement plan before work begins
• Do not sign completion paperwork until you are satisfied with the work. Inspect it carefully and raise any concerns immediately
• Keep all documentation including the guarantee certificate, TrustMark lodgement confirmation, and the Retrofit Coordinator’s report

If you are considering energy efficiency improvements for your home, whether through ECO4 or privately funded, getting the right installer is crucial. You can request a free quote from vetted, quality-assured installers through our service.

Frequently Asked Questions About ECO4 Complaints

How long does the ECO4 guarantee last and what does it cover?

The TrustMark guarantee for ECO4 installations lasts up to 25 years from the date of installation. It covers defects in workmanship and materials, including any consequential damage to your property caused by the defective installation. For example, if poorly fitted insulation causes damp that damages your plaster and decoration, the cost of repairing that damage is covered as well as the cost of fixing the insulation itself.

What if the installer who did my ECO4 work has gone bust?

The TrustMark guarantee includes financial protection specifically for this situation. If the original installer has ceased trading, TrustMark will appoint an alternative contractor to carry out the remediation work. The cost is covered by the financial protection fund, not by you. Contact TrustMark on 0333 555 1234 to start this process.

Can I get compensation for damage caused by poor ECO4 work?

Yes. The guarantee covers consequential damage, meaning damage to your property caused by the defective installation. If damp from poor insulation has ruined furniture, carpets or decoration, you can claim for the cost of replacement or repair. Keep receipts and photographs as evidence. For significant losses, you may also have a claim under consumer protection law. Citizens Advice can help you understand your options on 0808 223 1133.

I had ECO work done years ago under an older version of the scheme. Am I still covered?

Work carried out under earlier ECO schemes (ECO1, ECO2, ECO3) may have different guarantee arrangements depending on when the work was done and who carried it out. If the work was lodged with a guarantee scheme, that guarantee should still be valid. Check any paperwork you received at the time of installation. If you cannot find your guarantee documentation, contact TrustMark or the Green Deal Ombudsman service for help tracing your guarantee.

Should I accept a cash payment instead of remediation work?

Be very cautious about accepting cash settlements. The amount offered may not cover the full cost of having the work remediated by another contractor. If the defect is causing ongoing damage to your home, a cash payment does not fix the problem. In most cases, you are better off insisting on proper remediation work carried out to the correct standard. If you do consider a cash settlement, get an independent quote for the remediation cost first so you know the true figure. For advice on what good quality installation looks like for heat pumps, boilers and insulation, speak to our team.