MCS Certification Exposed: Lack of Verification Raises Questions

For years, MCS has successfully presented itself as the anchor institution of the UK’s domestic renewable energy transition, the arbiter of quality, the guardian of standards and the primary guarantor of consumer protection in the heat-pump sector. Its name and branding appear on every certificate used to unlock public subsidies. It is also in the process of being handed, by Government, a formal monopoly over the certification of heat pumps under major clean-heat programmes. And yet, when tested, the foundations of the scheme crumble into dust.

I put that system to a very simple examination. I asked MCS for the design documents underpinning my own heat-pump installation, a system I knew had been installed without a heat loss calculation, which is an explicit requirement of MCS standards. What followed was a remarkable display of evasiveness, contradiction and institutional hand-washing that revealed a certification process almost entirely divorced from verification.

I was told, in plain terms, that MCS “only has visibility of the certificate itself.” No design evidence. No heat loss. No emitter schedule. No commissioning reports. Nothing!

The certificate (the document bearing the MCS logo, used by Ofgem to release public funds) exists in the MCS database without, according to MCS, any supporting evidence being held, reviewed or validated by the organisation responsible for the scheme. It was only after repeated questioning that the full picture emerged: installers issue the certificates themselves. MCS doesn’t check the design data that would allow it to ascertain whether a heat pump has been correctly sized, commissioned or even honestly represented. More on that shortly.

This is not merely a procedural weakness; it is an institutional design that places “trust” where verification should be and “self-certification” where oversight is required. It exposes a scheme built not on assurance but deference… a structure in which every critical function is someone else’s responsibility.

And yet, when MCS’s chief executive, Ian Rippin, appeared before MPs in February 2025, he described MCS in emphatic, almost chest-thumping terms. “MCS provides a badge of quality,” he told Parliament. He spoke of “consumer protection,” of a “robust scheme,” of standards that “underpin confidence.” In another segment he claimed that MCS is “central to safeguarding households” and that the scheme “ensures installations are designed and delivered to a high standard.”

These statements sit in jarring contradiction to the reality exposed by my correspondence:

If MCS does not hold the design documents…

If it does not verify heat loss calculations…

If it does not confirm the system specification…

If it does not check the commissioning data…

…what exactly is this “badge of quality”?

On what basis is consumer protection delivered? What is MCS actually safeguarding? What is the MCS actually deeming to be ‘quality’.

What Rippin described in Parliament bears no relation to the process experienced by homeowners navigating failures in the real world. The gulf between rhetoric and reality is vast. And the consequences are tangible.

Consider the recent case of another homeowner who posted her story on the forums this week. Her experience reads like a condensed case study of everything structurally wrong with the scheme.

She was quoted for an 11 kW heat pump. She received a MCS certificate for an 11 kW heat pump. But the physical unit outside her home was a 9 kW model. The serial plate confirmed it. The manufacturer’s app confirmed it. A new MCS certificate then appeared (version 3) showing 9 kW. It had been generated without her knowledge. There had been no notification, no explanation, no red flag raised.

When she asked the installer for the original heat loss calculation, she was eventually given a recalculation created months later. one that required her to provide radiator sizes, used inconsistent room temperatures and did not match the original design assumptions. When she asked MCS directly whether they held the original heat loss calculation, the reply was: “We do not hold a copy.” The only record MCS holds (the sole artefact in its database) is the certificate produced by the installer.

Once again, all roads led away from MCS. She was told to contact the consumer code. Told to contact the Certification Body. Told to raise it with the installer. MCS displayed no curiosity about the existence of multiple certificates, no concern that an incorrect certificate had unlocked a public grant, no willingness to investigate whether an installer had submitted contradictory information and no inclination to review the homeowner’s detailed evidence. The file was simply passed elsewhere.

The parallels with my own experience are striking. The failures differ, but the response is identical: MCS declines to investigate. MCS does not request documentation. MCS does not evaluate compliance. MCS does not escalate. Instead, it retreats to a narrow procedural definition of its role that appears specifically designed to preclude accountability. The structure is circular: installers self-certify; Certification Bodies perform limited spot checks; consumer codes focus largely on contractual matters; and MCS itself (the body upon which government legitimacy relies) disclaims involvement in enforcement.

And yet in Parliament, Rippin asserted that “MCS ensures consumers can trust that installations meet the standards.” But trust is not created by words. It is created by a system capable of scrutiny. A system with access to evidence. A system that holds documentation. A system that investigates material discrepancies. MCS, by its own admission, does none of these things. The contradiction between the public promise and the private practice could not be starker.

The implications extend far beyond individual homeowners. The Government is now consolidating clean-heat certification under a single organisation whose own processes appear incapable of demonstrating compliance with the standards it claims to uphold. The risk is not theoretical; it is systemic. A scheme with no evidential audit trail cannot meaningfully protect consumers, cannot safeguard public funds, cannot uphold design standards and cannot credibly act as the backbone of a national transition.

In practice, this results in homeowners left with inadequate systems and no recourse; installers capable of delivering excellent work dragged down by the failures of those exploiting loopholes; and a national heat pump programme whose credibility is fragile at best.

MCS will say that enforcement is the role of others. But the unavoidable truth is that a standards regime that allows certificates to be issued without verifying the underlying evidence is not a standards regime in any meaningful sense. It is a label-printing service; a scheme that confers the illusion of oversight without any of its substance.

I believe the UK needs a certification framework capable of scrutiny, transparency and enforcement. It needs an organisation that holds evidence, interrogates discrepancies and defends the public interest. MCS, on the evidence of both direct experience and systemic pattern, is not that organisation.

The stakes (consumer confidence, industry credibility and the pace of national decarbonisation) demand better than a structure built on self-certification and obscured responsibility. The Government has placed extraordinary reliance on a scheme whose internal architecture cannot support the weight of its public claims. Unless that changes, the transition to clean heat risks being undermined not by technology or installers but by the very institution entrusted to safeguard its integrity.