The Boiler Upgrade Scheme (BUS) has changed again. Now, air-to-air heat pumps become eligible, EPC requirements are relaxed, and greater flexibility is introduced for heat pumps alongside other electric appliances.
Good. But one line hasn’t moved.
Fossil-fuel hybrid systems remain outside the BUS. A household can get £7,500 towards an air source heat pump. Combine it with a gas boiler and they get nothing. The government has made its position clear.
Fine. But here’s the problem: grant eligibility is not the same as good heating advice, and the industry needs to stop treating it as though it is.
Inta is firmly pro-heat pump. We have invested in products that help installers fit, protect and optimise air source heat pump systems because we believe they are central to the future of domestic heating. In new builds and suitable retrofits, a full heat pump installation is the right answer. Nobody serious is arguing otherwise.
But the UK’s housing stock is not made up of easy retrofits.
Millions of older properties were built around high-temperature heating, combi boilers, existing radiator systems and decades of customer expectation. Some convert easily. Others can, but only at a cost, disruption level and confidence threshold that stops the decision dead.
That is where the policy debate has become too rigid – and where the industry is in danger of following it.
A heat-pump-led hybrid is not an argument against electrification. It is a practical route into electrification for homes where the alternative isn’t a full heat pump installation this year. It’s another decade of boiler-only heating. That distinction matters enormously.
Last year, Worcester Bosch and the University of Salford produced the clearest UK evidence yet on what a properly configured hybrid actually delivers. Their trial ran in a full-scale reconstruction of a pre-1919 solid-wall end-terrace – no fabric upgrades, no ideal conditions – with the heat pump set as the primary source.
The results were unambiguous. The heat pump delivered a weighted average of 94% of annual heat demand. At 7°C and above, it handled 100% of the space heating requirement. Even at -3°C, it still contributed more than 70%. Against a boiler-only baseline, the system delivered a 1,270kg CO₂ reduction – around 77% of the carbon saving of a full heat pump.
That is not a token gesture at decarbonisation. That is a substantially electrified heating system, with a boiler kept in reserve for when it is genuinely needed.
The market data underlines why this matters. UK heat pump sales hit a record 125,037 units in 2025, up 27% year on year. Progress, yes – but the growth rate has already slowed from 2024’s 56% surge, and the HPA has been clear that the sector needs around 33% compound annual growth to reach 450,000 installations a year by 2030. We are not on that trajectory.
The homes that could tip the numbers are not the easy ones. They are the older properties, the reluctant customers, the jobs where full conversion is technically possible but commercially and practically out of reach for the household in front of the installer.
For those homes, the choice isn’t between a full heat pump and a hybrid. It’s between a hybrid and doing nothing.
If a hybrid system puts the heat pump in charge for 94% of the year, slashes gas use, reduces carbon materially and gives a hesitant homeowner a route they are willing to take – why would the industry dismiss it simply because it doesn’t qualify for a grant?
The government may not be ready to back fossil-fuel hybrids through the BUS. That is now settled. But the absence of a grant does not remove the value of the technology.
More heat pumps fitted. Less gas burned. Homeowners who would otherwise wait a decade making the move now. That should be the test – not which box a system ticks on an Ofgem application form.
On that test, heat-pump-led hybrids still deserve to be taken seriously. The industry should say so.
