string(99) ""

What to do if things go wrong

Please note, MCS can only assist if:

  • The installer is still trading
  • The installer is MCS Certified
  • You have submitted a formal letter of complaint to the installer giving them an opportunity to respond

In situations where MCS cannot assist there are other organisations who may be able to. Please see the section on “Advice for when MCS Can’t Help” below for further guidance.


A complaint might include the following:

  • Faulty system or individual components
  • Issues with the standard of workmanship
  • Electrical or safety issues
  • Issues relating to the system’s design, size or performance
  • Non-compliance with relevant installation Standards
  • Handover pack incomplete
  • Missing or incorrect MCS certificate
  • Any instance which may bring the MCS scheme into disrepute

If you have concerns about your installation, please complete the below steps:

Step 1 – Send a formal letter of complaint to the Installer who carried out the work and give them the opportunity to resolve the issue. Please note you should be prepared to allow your Installer access to your installation to enable them to address or resolve your complaint.

Step 2If you have issued a formal letter of complaint to the Installer and they have failed to resolve your complaint, within 14 days, please complete all of the information on theSomethings Gone Wrong” form and submit it to us.

We seek to acknowledge all submitted forms within 5 working days; if you haven’t heard anything within that timescale please get in touch to check we have received it.

Before submitting this form, please ensure you have completed the first step in the process of submitting a formal letter of complaint to your installer.

Once we have received your “Something’s Gone Wrong” form, our Helpdesk Team will triage this and inform you of the next steps. You may be requested to complete a complaint form with supporting evidence at this stage; a link to the complaint form will be provided to you. This will then be referred by MCS to the Installer’s Certification Body and/or Consumer Code to investigate.


UKAS accredited Certification Bodies certify installers that demonstrate the competence required to fulfil MCS Standards. This is done on an ongoing basis and they undergo annual surveillance visits in order to retain their membership.


It is mandatory for all of our Installers to be registered with a Consumer Codes Approval Scheme (CCAS).

It is facilitated self-regulation.

It aims to promote consumer interests by setting out the principles of effective customer service and protection. It goes above and beyond consumer law obligations and sets a higher standard.

Your Installer’s Consumer Code can assist with pre-sale and contractual issues, this may include:

  • Communication issues and customer service problems
  • System installed is not what was agreed in the contract
  • Wrong brand of product
  • Damage to property
  • Failure to refund a deposit or advance payment
  • Incomplete installation and/or contract
  • Incorrect provision of information relating to eligibility, deadlines or application procedures for grants or other incentive schemes
  • Deposit insurance or insurance backed guarantee
  • Misleading information regarding the financial benefit of the system
  • Potential breaches of the Consumer Code
  • System faults arising during the period of the insurance backed guarantee


MCS help and advice

If you have completed the above steps with MCS we will be aware of your case. However, if you have been in contact with the Installer’s Certification Body and/or Consumer Code directly, we will need you to complete a Somethings Gone Wrong Form indicating that you wish to submit an escalated complaint.

We can only investigate installations, associated handover documentation and installer conduct, where the Certification Body and/or Consumer Code has fully exhausted their complaint process, or for some reason have not been able to assist and the complaint has still not been resolved to your satisfaction.

If following investigation an Installer has failed to comply, the ultimate sanction is removal of their licence to operate under the MCS scheme. This is an MCS decision and is based on multiple factors, including the installers complaint history.

MCS do not have the authority to enforce the following:

  • To award compensation or other financial redress.
  • Arrange for installation removal or refunds.
  • Appoint another installer to undertake remedial work on your behalf.



Whether MCS can help you to resolve a complaint is very much dependent on the circumstances.

  • In general, if your installer is no longer trading, MCS is unable to assist. You should check your insurance backed warranty.
  • We can’t address complaints relating to installations on which remedial work has been undertaken by another installer or third-party, unless they were directly appointed by your installer through a compliant contractual arrangement.
  • We may not be able to assist if you’ve begun legal proceedings against the installer (or the installer against you)

If we aren’t able to take action, there are other organisations which might be able to help:

Organisation & Contact Details Organisational Summary
Address: 2 Pine Trees, Chertsey Lane, Staines-upon-Thames, TW18 3HR
Tel: 01784 429000
Accreditation Scheme for the MCS Certification Bodies. UKAS can assist in complaints regarding the way that your complaint has been handled by the relevant Certification Body.
Trading Standards
Address: Local offices (website search)
Email: Provided by local area office
Tel: 03444 111 444
Contact though Citizens’ Advice. Complaints about potentially fraudulent activity, or no longer MCS certified. Able to provide advice on a range of topics including:

  • Building and home improvements
  • Problems with products
  • Problems with service providers
  • Protection for the consumer
  • Consumer rights
  • Consumer contracts
  • Unsafe or dangerous items
  • Fake or counterfeit items
Department of Energy Security and Net Zero (DESNZ)
Address: 55 Whitehall, London, SW1A 2HP, United Kingdom
Tel: 020 7215 5000
For complaints about Government energy policy and legislation.
Address: 10 South Colonnade, Canary Wharf, London, E14 4PU
Tel: 0300 003 2289
Queries and complaints about domestic RHI applications made before 31 March 2022 (the DRHI is now closed to new applications) and the Boiler Upgrade Scheme.
Energy Ombudsman
Address: Ombudsman Services: Energy, PO Box 966, Warrington, WA4 9DF
Email: N/A
Tel: 0330 440 1624
Provide independent and impartial decisions on complaints against installers within the energy sector. Typically, if the installer’s Certification Body, Consumer Code and/or MCS has been unable to resolve a complaint.
Energy Performance Certificates (EPCs)
Address: N/A
Tel: 01392 690428
The Domestic Energy Performance Certificate Register is operated by Landmark on behalf of the Government. Facilitate retrieval of an EPC, or regarding complaints about an EPC (e.g. incorrect rating given). Make a formal complaint to the Energy Assessor in the first instance. If unresolved, the EPC public enquiry helpdesk (Landmark) can provide details of the relevant accreditation scheme.
Companies House
Address: Registrar of Companies (England and Wales) Crown Way, Cardiff, CF14 3UZ, DX 33050 Cardiff
Tel: 0303 1234 500
All limited companies are registered at Companies House. You can find company information published on the website.