2025 will be remembered as the year the UK heat pump industry lost the last shred of accountability it had left. The Department for Energy Security and Net Zero (DESNZ) has officially confirmed that MCS will become the sole certification body for clean heat schemes, including the Boiler Upgrade Scheme (BUS), ECO4 and the Clean Heat Market Mechanism. It’s a move that cements a monopoly and one that we have warned against.
This is not progress. It’s a catastrophic mistake.
For those of us at Renewable Heating Hub who engage with thousands of homeowners (through our forums, emails and private messages) this is personal. 2025 has seen more failed heat pump installations than ever before. Behind every number is a homeowner who believed they were investing in a sustainable, efficient future. Instead, many are left with systems that barely heat their homes, drain their finances and leave them stuck in an endless complaints process that goes nowhere.
Every single one of these failed installations has an MCS badge stamped on it and a £7,500 Boiler Upgrade Scheme grant attached.
And the government’s answer? Give MCS even more power.
Let’s be absolutely clear: the issue at the heart of this isn’t complex… it’s the total lack of a defined performance standard. Right now, there is no mandatory benchmark for how an installed heat pump system should perform. The only “requirement” that exists is a line buried in regulation stating that a heat pump must have a seasonal coefficient of performance (SCOP) of at least 2.8 as determined by an “approved test method.” That means the unit itself (the hardware) needs to hit 2.8 in laboratory conditions. It says absolutely nothing about how the system performs once installed in a real home.
This is why so many MCS-certified heat pump systems in the UK are running at sub-2.7 SCOPs, well below acceptable efficiency. Homeowners are unknowingly living with systems that are wasting energy, inflating bills and undermining public trust in renewable heating. Yet MCS continues to certify these installations as compliant, because the regulation doesn’t measure actual system performance.
It’s a loophole big enough to drive an oil tanker through.
And when things go wrong (as they so often do) the situation only gets worse. The complaints process is a labyrinth designed to wear homeowners down. Cases routinely drag on for years, some now reaching four or even five years on our forums without resolution. Homeowners have been passed from MCS to RECC or HIES to installers to cert bodies in an endless cycle of finger-pointing and deflection. For many, the experience is emotionally exhausting and financially devastating.
Frankly, it’s a disgrace.
What makes it even harder to swallow is the fact that every one of these botched systems was effectively underwritten by public money. £7,500 handed out per install under the Boiler Upgrade Scheme and every one of them rubber-stamped by MCS. This is the mainstream, government-backed standard.
And let’s not forget the environmental cost. A poorly performing heat pump doesn’t just waste money, it wastes energy. A system running at a SCOP of 2 instead of 3.5 uses 75% more electricity to deliver the same heat. That’s more carbon, more grid demand and more pressure on an already strained energy system. The government loves to talk about Net Zero, yet continues to endorse a framework that actively undermines it.
Allowing MCS to retain exclusive control over certification is, frankly, a cataclysmic error. Competition isn’t a threat to standards, it’s the only path to improving them. Flexi-Orb, for example, has built a credible, UKAS-accredited alternative framework that prioritises homeowner protection, installer accountability and system performance. But instead of fostering a competitive environment, DESNZ has chosen to double down on the same failing structure that has delivered years of mediocrity and misery.
This is not about policy nuance or procedural alignment… it’s about protecting a monopoly. MCS is now a gatekeeper not just of standards but of access to public funds. If you’re not MCS-certified, you’re locked out. That means innovation is stifled, consumer choice is throttled and installers who want to do things differently are pushed to the margins.
The result? More of the same. More homeowners left cold. More wasted public money. More distrust in an industry that desperately needs credibility.
It’s worth remembering that MCS has had over a decade to get this right. In that time, it has presided over one of the most fragmented, inconsistent and opaque certification systems in the UK. Its response to legitimate criticism has been platitudes about “raising standards” and “protecting consumers”, slogans that sound good in press releases but ring hollow in practice.
Now, with government backing, MCS is free to operate unfettered, accountable to no one, shielded from competition and bankrolled by public money. It is the very definition of institutional complacency and homeowners will be the ones who pay the price.
There is still time for this to be challenged, but the industry needs to wake up. Installers, manufacturers, policymakers (anyone who genuinely cares about the future of low-carbon heating) should be outraged by this decision. Because when accountability dies, quality follows.
The government’s decision to hand MCS total control isn’t about raising standards. It’s about protecting a broken system. And that, in every sense, is a national disgrace.