Raising a problem after an ECO4 installation: what UK households should check (2026)

Guide by ApplyFreeBoiler.uk (Reliant Energy Solutions Ltd), a heating and insulation installer in Bury, Greater Manchester. We are not the government, Ofgem or an energy supplier.

Most ECO4 installations go smoothly, but if something is not right afterwards it helps to know how to raise it calmly and keep good records. This checklist is general information from ApplyFreeBoiler.uk, a heating and insulation installer in Bury. It is not legal advice, and we are not the government, Ofgem or an energy supplier.

1. Write down what is wrong and when it started

Note the problem in plain words, the date you first noticed it and anything that makes it better or worse. Photos or short videos of leaks, damp patches, error codes or unfinished work are very useful later.

2. Contact the installer first, in writing

Start with the company that did the work. Email or write to them so there is a dated record, describe the problem, attach photos and ask when they can come back. Keep a copy of everything you send and receive.

3. Keep all the paperwork together

Gather the survey details, any agreement you signed, commissioning records, warranty documents and handover notes. These show what was installed, when and by whom, which helps whoever looks into the problem.

4. Ask which energy supplier funded the work

ECO4 work is funded through energy suppliers. If the installer does not resolve the problem in a reasonable time, ask them which supplier funded your installation so you know who else to contact.

5. Get free independent advice if you are stuck

Citizens Advice can explain your options as a consumer and how to take a complaint further. If you are unsure about safety, such as a gas smell or signs of carbon monoxide, treat it as an emergency and call the gas emergency number straight away.

6. Be wary of cold calls offering to fix it

If you are contacted out of the blue by someone offering to put right ECO4 work for a fee, be cautious. Check who they are independently before giving any details or letting anyone into your home.

7. Check funding and local figures

See ECO measures by council on ApplyFreeBoiler.uk, built from DESNZ Household Energy Efficiency statistics, to see how many ECO measures have been installed in your local authority area. Use the ApplyFreeBoiler.uk eligibility check to see whether an ECO4 heating or insulation pathway may be available for your home in England, Scotland or Wales. ECO4 is due to close on 31 December 2026.