The Complete Guide to the UK Boiler Upgrade Scheme: How to Claim Your £7,500 Heat Pump Grant
What Is the Boiler Upgrade Scheme?
The Boiler Upgrade Scheme (BUS) is a UK government grant programme designed to accelerate the transition away from fossil fuel heating by offering upfront financial support toward the cost of installing a heat pump.
Managed by Ofgem on behalf of the Department for Energy Security and Net Zero (DESNZ), the scheme provides a flat grant of £7,500 applicable to both air source heat pumps (ASHP) and ground source heat pumps (GSHP).
This represents a significant proportion of the total installation cost, which typically ranges from £10,000 to £18,000 depending on system size, property characteristics, and installation complexity.
Introduced in 2022 and originally scheduled to run through to 2025, the scheme has been extended and revised several times, with funding allocated through quarterly budget caps.
The scheme operates on a first-come, first-served basis, meaning applicants apply through an MCS-certified installer who applies on the customer's behalf.
Unlike earlier schemes such as the Renewable Heat Incentive (RHI), the BUS provides a one-time upfront grant rather than ongoing quarterly payments, which simplifies cash flow planning considerably for homeowners.
Key Fact: As of the current scheme rules, homeowners replacing an existing fossil fuel boiler (gas, oil, or coal) in a property that is at least 10 years old may qualify for the full £7,500 grant.
Properties connected to the gas grid must replace their gas boiler specifically — switching from one gas boiler to another does not qualify.
How the Grant Amounts Work
The Boiler Upgrade Scheme offers fixed grant values rather than percentage-based subsidies.
The current rates are:
| Technology | Grant Amount | Typical Installation Cost (pre-grant) | Your Approximate Cost After Grant |
|---|---|---|---|
| Air Source Heat Pump | £7,500 | £10,000 – £14,000 | £2,500 – £6,500 |
| Ground Source Heat Pump | £7,500 | £14,000 – £19,000 | £6,500 – £11,500 |
| Biomass Boiler | £5,000 | £10,000 – £17,000 | £5,000 – £12,000 |
The most common choice by far is the air source heat pump, which accounts for approximately 85–90% of all BUS installations.
This is largely because ASHPs require no groundworks — the outdoor unit sits against an exterior wall — making installation faster, cheaper, and less disruptive.
Ground source heat pumps involve boreholes or trenches for ground loops, which can add £3,000–£8,000 to the total cost and are only practical where adequate garden space exists.
Data Point: According to Ofgem's published scheme data, over 100,000 heat pump grants have been issued under the BUS since its launch in 2022 through to early 2025, with applications accelerating as installation costs have normalised and consumer awareness has grown.
Am I Eligible?
The Criteria Explained
Understanding eligibility is where many applicants stumble.
The scheme has specific requirements that must all be met simultaneously:
- Property age: The property must have been built and occupied as a dwelling for at least 10 years.
New-build properties are generally excluded.
- Existing heating system: You must be replacing an existing fossil fuel heating system — gas boiler, oil boiler, coal fire, or electric storage heaters.
If your property has no existing heating system (e.g., a recent conversion), you may need to demonstrate prior fossil fuel use.
- Property type: The scheme covers domestic dwellings in England and Wales.
Scotland and Northern Ireland operate separate schemes.
Owner-occupied and privately rented properties are eligible; social housing is not covered by BUS.
- Installation standard: The heat pump must meet minimum efficiency standards and be installed by an installer registered with the Microgeneration Certification Scheme (MCS).
- No double-dipping: You cannot have previously received public funding (including Green Deal finance, the earlier Renewable Heat Premium Payment, or ECO grants) for the same measure in the same property.
Pro Tip — Renting Out Your Property: If you are a private landlord, you can apply for the BUS, but you must obtain tenant consent and ensure the installation meets the same technical standards.
There is no additional landlord-specific grant uplift, so the £7,500 figure applies to all applicants equally regardless of tenure.
The Step-by-Step Application Process
One of the practical advantages of the Boiler Upgrade Scheme is that homeowners do not submit applications directly.
The process is handled by your chosen installer, which removes much of the administrative burden.
Here is how it works in practice:
Step 1: Assess your property and obtain quotes. Before committing, you need at least two or three quotes from different MCS-certified installers.
A reputable installer will conduct a thorough survey — not just a visual inspection — examining your home's heat loss profile, radiator sizes, hot water demand, and insulation levels.
Quotes that skip this assessment should be treated with caution.
Step 2: Confirm the installer will handle the BUS application. Ask your chosen installer explicitly whether they will submit the grant application on your behalf and what their process is.
They will need your property details, existing heating system information, and Energy Performance Certificate (EPC) reference number.
Step 3: Installer submits the grant application to Ofgem. The installer applies for a BUS grant voucher on your behalf.
Ofgem typically issues a voucher within a few working days.
Vouchers are valid for three months, though extensions can be requested in certain circumstances.
Step 4: Installation takes place. Once the voucher is confirmed, the installer proceeds with the heat pump installation.
The work must be completed before the voucher expires.
Step 5: Installer redeems the voucher. After installation, your installer notifies Ofgem that the work is complete.
The £7,500 is then paid directly to the installer, and they deduct this from your final invoice.
You pay only the balance.
Data Point: The average time from initial survey to completed installation under the BUS is approximately 6–12 weeks, though this varies significantly by installer, region, and time of year.
Spring and summer tend to be quicker as this is the off-peak period for heating engineers.
"Getting three surveys done before signing anything with anyone was the single most valuable thing I did.
One installer wanted to install an undersized unit that would have struggled in winter; another quoted for a system that required a completely new radiator layout.
The third was honest about what was needed and what wasn't." — Homeowner, North Yorkshire, 2024
What Preparation Work Is Actually Needed?
Here is the critical point that many marketing materials gloss over: the £7,500 grant covers the heat pump and its installation, but it does not cover the preparation work that often makes the difference between a heat pump that performs well and one that disappoints.
Heat pumps operate most efficiently at lower flow temperatures than traditional boilers — typically 45–55°C rather than 70–80°C — and this has direct implications for your existing heating system.
Before committing to a heat pump installation, you should factor in the following potential additional costs:
- Loft insulation: If your loft insulation is below 270mm (current recommended depth), topping it up costs approximately £300–£800 depending on property size.
- Cavity wall or solid wall insulation: Insulating exterior walls can cost £1,000–£5,000 depending on wall type and property size, but it has an outsized impact on heat loss reduction.
- Radiator upgrades or additions: Larger radiators or additional radiators may be needed to deliver the same heat output at lower water temperatures.
A full radiator replacement programme across a three-bedroom semi-detached house might cost £2,000–£4,000.
- Hot water cylinder replacement: Many heat pumps require a cylinder with a larger coil surface area to achieve hot water temperatures efficiently.
A new dual-coil cylinder costs £500–£1,200 installed.
- Buffer tank: Most ASHP installations benefit from or require a buffer tank to smooth the start-stop cycle.
This adds £300–£600 to installation costs.
Pro Tip — Get a Heat Loss Calculation First: Ask your installer for a detailed heat loss calculation (using software such as Heat Geek, Stroma, or SAP) before quoting for the heat pump itself.
This document tells you exactly what size heat pump you need and what improvements are most cost-effective.
Any installer who quotes without conducting this calculation is not following best practice.
This single step can save you thousands in the long run by right-sizing the equipment from the start.
Running Costs: What to Realistically Expect
One of the most common reasons homeowners hesitate is concern about running costs.
The honest answer is more nuanced than either the optimists or sceptics suggest.
A correctly sized and properly installed heat pump in a well-insulated property will typically reduce heating bills — but the extent depends heavily on three factors: the efficiency of the heat pump itself, the insulation standard of the property, and the tariff you are on.
Modern air source heat pumps achieve a Seasonal Coefficient of Performance (SCOP) of between 2.8 and 4.0, meaning for every kilowatt-hour of electricity consumed, they deliver 2.8 to 4 kilowatt-hours of heat.
Ground source heat pumps typically perform better, with SCOP values of 3.5 to 5.0.
For a typical three-bedroom semi-detached house in England with an annual heating demand of 12,000 kWh:
- Gas boiler at current UK prices (~8p/kWh): approximately £960 per year in gas
- Heat pump at the same demand with SCOP 3.0 and electricity at 24p/kWh: approximately £960 in electricity
- Heat pump with a dedicated time-of-use tariff (e.g., Octopus Agile) at 7p/kWh off-peak: approximately £280 per year
The running cost comparison improves significantly if you are currently heating with oil, coal, or electric storage heaters — all of which are substantially more expensive per kilowatt-hour than natural gas or a heat pump on an Economy tariff.
Data Point: The Energy Saving Trust estimates that a typical household switching from a gas boiler to an air source heat pump in a well-insulated property can expect annual running costs to remain broadly similar — with the key variables being tariff choice and property insulation quality.
In poorly insulated properties, running costs can increase materially unless insulation improvements are made alongside the installation.
Common Mistakes to Avoid
Having reviewed numerous case studies and spoken with installers operating under the BUS, several recurring pitfalls emerge:
Choosing on price alone: The cheapest quote is frequently not the best one.
An installer who undercuts significantly may be sizing the heat pump incorrectly, cutting corners on pipework, or using lower-quality components.
The MCS certification guarantees a baseline standard but does not guarantee quality of design.
Neglecting the controls: Heat pumps work best with appropriate controls, including weather compensation and intelligent programming.
Budget an additional £300–£800 for proper controls — this is not optional if you want the system to perform as designed.
Assuming it will be silent: ASHP outdoor units produce fan noise.
Modern units are considerably quieter than earlier models, but they are not silent.
Installer positioning matters enormously — avoid mounting units directly beneath bedroom windows or near neighbour boundaries without acoustic assessment.
Not checking your EPC: While the BUS does not mandate minimum EPC levels in the same way the ECO4 scheme does, a poor EPC rating will mean higher running costs and potentially insufficient comfort.
Some Local Authorities have their own complementary schemes that can help fund insulation alongside BUS.
Check with your local authority before proceeding.
The Bigger Picture: What the Grant Does and Does Not Do
The £7,500 Boiler Upgrade Scheme grant is generous by historical standards and meaningfully reduces the upfront cost barrier to heat pump adoption.
However, it should be viewed as part of a broader upgrade strategy rather than a standalone solution.
The government has consistently signalled that the BUS is one component of a long-term strategy that will eventually require homeowners to move away from fossil fuel heating — with future regulations likely to restrict new gas boiler installations in a manner similar to the 2024 Future Homes Standard discussions.
For homeowners currently on mains gas, the financial case for switching is compelling primarily if you are facing boiler replacement anyway.
A boiler replacement at the end of a boiler's natural lifespan — typically 10–15 years — represents the lowest-disruption opportunity to make the switch, because the preparatory work (potentially new radiators, cylinder, controls) would likely be needed regardless.
For homeowners on oil or coal, the economics are even more favourable.
The £7,500 grant goes further relative to the cost of replacing an oil boiler (£3,000–£6,000 for a like-for-like replacement), and the running cost saving compared to oil at current prices is typically 30–50% for an equivalent heat output.
Checklist Before You Apply
- Confirm your property has been occupied for at least 10 years and is in England or Wales
- Verify you are replacing a fossil fuel heating system (gas, oil, coal)
- Check that no previous government grant has been claimed for the same heating measure at this property
- Obtain quotes from at least two MCS-certified installers
- Ensure each installer conducts a heat loss calculation, not just a visual survey
- Discuss and obtain quotes for any necessary preparation work — insulation, radiator upgrades, cylinder replacement
- Confirm the installer's process for applying for the BUS voucher on your behalf
- Clarify the exact amount you will pay after the grant is deducted from the invoice
- Check the voucher validity period and agree a realistic installation date with your chosen installer
- Ask about warranty terms, post-installation support, and what happens if issues arise
Final Thoughts
The Boiler Upgrade Scheme represents a genuine opportunity for UK homeowners to future-proof their heating systems at a substantially subsidised cost.
The grant of £7,500 removes the largest single barrier — upfront capital cost — and the scheme's structure, with installer-led applications and direct payment to contractors, keeps the process straightforward for homeowners willing to invest time in understanding what they are buying.
The quality of the outcome, however, depends almost entirely on the quality of the installation — specifically on correct sizing, proper preparation of the property, and appropriate controls.
A heat pump installed in an unprepared property by an installer who cuts corners will deliver poor performance and high bills, regardless of how attractive the grant figure looks on paper.
Spending time getting the specification right before signing a contract is the single most important step in this process.
The grant is a catalyst, not a guarantee.