Navigating the UK Boiler Upgrade Scheme
The Boiler Upgrade Scheme can help reduce the upfront cost of switching to low-carbon heating in England and Wales. Designed to support the move away from traditional fossil-fuel systems, the scheme makes technologies such as heat pumps and certain biomass boilers more financially accessible for eligible properties.
Because the scheme is installer-led, it is relevant to both property owners exploring heating upgrades and installers supporting clients through the application and specification process. The value of the grant is deducted from the installation cost, helping to make low-carbon heating a more viable option across a wider range of projects.
What is the Boiler Upgrade Scheme?
The Boiler Upgrade Scheme, often shortened to BUS, is a government-backed grant available in England and Wales. Its purpose is to encourage the replacement of older, higher-carbon heating systems with lower-carbon alternatives.
Although the scheme is often associated with domestic boiler replacement, its scope is broader than that. Depending on the property and the heating setup being replaced, the scheme may also be relevant to landlords, owners of second homes and some small non-domestic buildings.
For homeowners, the scheme can make a major heating upgrade more affordable. For installers, it provides an important route to support clients moving towards compliant, lower-carbon systems.
How much can be claimed?
At the time of writing, the main Boiler Upgrade Scheme grants are:
- £7,500 towards an air source heat pump
- £7,500 towards a ground source heat pump
- £5,000 towards a biomass boiler
Only one grant can be claimed per property, and the installation must meet the relevant technical and eligibility requirements.
For both installers and homeowners, the practical value of the scheme lies in reducing upfront cost while making long-term system performance part of the wider conversation.
Who is eligible?
Eligibility generally depends on the type of property, the heating system being replaced and the technology being installed.
In most cases, the property owner must own the property and be replacing an existing fossil-fuel or electric heating system with an eligible low-carbon alternative. The property will usually also need a valid Energy Performance Certificate, and the installation must be carried out by an MCS-certified installer.
The scheme cannot generally be used to replace an existing low-carbon heating system, and the same installation cannot normally receive overlapping public funding for the same purpose.
From an installer perspective, this makes early eligibility checks particularly important. From a homeowner perspective, it means the first step should usually be an assessment of both the property and the current heating arrangement before costs are compared.
Are new build properties eligible?
This is one of the areas where confusion often arises.
Most new build properties are not eligible for the Boiler Upgrade Scheme, but there are important exceptions. Self-build properties may qualify where the relevant criteria are met. There are also circumstances in which a completed new build containing a fossil-fuel boiler may still fall within the scope of the scheme.
For installers, that means careful review of project status and ownership structure is essential before any assumptions are made. For homeowners, it means that a new build should not automatically be ruled in or out without checking the current criteria in detail.
What about biomass boilers?
Biomass boilers are included within the scheme, but they are more restricted than heat pumps.
In most cases, biomass support is limited to properties that are both:
- Located in a rural area
- Not connected to the gas grid
That makes biomass a more specialist route rather than a general low-carbon alternative for every project. In many cases, air source or ground source heat pumps will be the more widely applicable option.
For installers, biomass tends to be a more selective recommendation based on property location and fuel access. For homeowners, it is often one of several routes to consider rather than the default alternative.
Air source heat pumps
Air source heat pumps remain the most widely discussed technology under the Boiler Upgrade Scheme. These systems extract heat from the outside air and use it to provide heating and, in many cases, hot water for the property.
They can be suitable for a broad range of homes when paired with appropriate insulation levels and correctly sized heat emitters such as radiators or underfloor heating. Although upfront costs are usually higher than for a standard boiler replacement, the available grant can significantly improve affordability.
For homeowners, air source heat pumps are often the first serious option when moving away from gas, oil or LPG heating. For installers, they remain the most common low-carbon system type within the current grant structure.
Ground source heat pumps
Ground source heat pumps use stored heat from the ground to provide low-carbon heating. Installation costs are usually higher than those of air source systems, but the technology can offer strong long-term efficiency and reliable performance.
These systems are often best suited to properties with sufficient outside space for ground loops or to projects where a more substantial heating redesign is already being considered.
Because the grant level matches that of air source heat pumps, the choice between the two generally depends on site conditions, installation complexity, budget and wider project goals.
Air-to-air heat pumps and the Boiler Upgrade Scheme
Air-to-air heat pumps are becoming an increasingly important part of the low-carbon heating discussion, particularly as the scheme evolves.
Unlike air-to-water heat pumps, which heat water for radiators, underfloor heating and domestic hot water, air-to-air systems heat the internal air directly through indoor and outdoor units. They can also provide cooling during warmer weather, making them particularly attractive for flats, smaller homes and properties without a traditional wet central-heating system.
This makes them relevant not only to homeowners looking for flexibility, but also to installers working with properties where a full wet system may be harder to justify on cost, layout or practicality grounds.
One important technical point is that air-to-air heat pumps do not usually provide domestic hot water, so a separate hot water solution is typically needed. That should always be part of the conversation at design stage.
Government support has been announced to include air-to-air heat pumps, with a £2,500 discount under the scheme. This marks a significant development because it broadens the scheme’s relevance beyond the standard boiler-to-air-source-heat-pump pathway.
For homeowners, that could create a more practical route for properties that do not lend themselves easily to an air-to-water setup. For installers, it opens the door to a wider range of property types and system recommendations, especially where heating and cooling are both priorities.
Because guidance has not always been updated consistently across every source, current eligibility and live availability should always be confirmed before a recommendation is treated as final.
Why air-to-air heat pumps matter
The growing role of air-to-air heat pumps matters because it expands the conversation around low-carbon heating.
Not every property is suited to a wet central-heating system. Some flats, smaller homes and properties currently using electric panel heaters or no central heating at all may be better suited to an air-to-air solution. The ability to provide both heating and cooling also makes the technology increasingly relevant in projects where year-round comfort is part of the brief.
For installers, this means greater flexibility in matching technology to property type. For homeowners, it means the available options are becoming broader and more tailored than a simple boiler replacement model might suggest.
How does the application process work?
The Boiler Upgrade Scheme is generally not applied for directly by the homeowner. Instead, the process is usually managed by the installer.
A typical process looks like this:
- An MCS-certified installer assesses the property and recommends a suitable system
- Eligibility is checked against the scheme criteria
- A quotation is issued with the grant value reflected where appropriate
- The installer submits the application on behalf of the property owner
- The grant is deducted from the installation cost
For installers, that means accurate specification and eligibility checks are essential from the start. For homeowners, it means the process is usually more straightforward than a direct grant application.
Is there VAT relief too?
Alongside the grant itself, temporary VAT relief on the installation of certain energy-saving materials, including heat pumps, can also improve overall value.
This is relevant to both sides of the project. For homeowners, it can reduce the final installed cost. For installers, it can make project pricing more competitive and easier to position against conventional boiler replacement.
When comparing systems, the full installed cost after grant support and any applicable tax relief should always be considered rather than looking only at headline product or labour costs.
Does the scheme apply across the UK?
The Boiler Upgrade Scheme applies to England and Wales.
In Scotland, separate support may be available through Scottish funding routes. In Northern Ireland, local support mechanisms apply rather than the Boiler Upgrade Scheme.
For both installers and property owners, this means location is a fundamental starting point when assessing available support.
Is the Boiler Upgrade Scheme worth it?
For many projects, the answer is yes.
The Boiler Upgrade Scheme can significantly reduce the upfront cost of switching to low-carbon heating, making air source and ground source heat pumps more accessible. With the addition of support for air-to-air heat pumps, the scheme is becoming relevant to a broader range of homes and layouts as well.
However, the right solution depends on more than grant value alone. Insulation levels, heat loss, available space, emitter suitability, hot water requirements and the nature of the existing heating setup all remain important.
For installers, that means scheme value should sit alongside sound design and system suitability. For homeowners, it means the best outcome usually comes from looking at whole-property performance rather than focusing on grant funding in isolation.
Final thoughts
The Boiler Upgrade Scheme remains one of the most important incentives available for moving away from traditional fossil-fuel heating in England and Wales.
While air source heat pumps continue to dominate much of the conversation, the inclusion of air-to-air heat pumps represents an important shift. It shows that low-carbon heating is not one-size-fits-all and that different properties may require different solutions depending on layout, infrastructure and heating demand.
For homeowners, that creates more flexibility when considering the next heating upgrade. For installers, it creates wider opportunities to recommend the most suitable low-carbon system for each project rather than forcing every property into the same pathway.
As the scheme develops, air-to-air heat pumps are likely to become an increasingly important part of that discussion.
