Boiler Upgrade Scheme (BUS) Guide: £7,500 Heat Pump Grant
TLDR: The Boiler Upgrade Scheme (BUS) offers £7,500 grants for heat pump installations in England and Wales. Requirements: EPC rating of D or better, MCS-certified installer, no previous BUS funding for the property. The scheme runs until at least 2028. This guide explains exactly how the process works, what you'll really pay after the grant, and how to avoid common pitfalls.
What Is the Boiler Upgrade Scheme?
The Boiler Upgrade Scheme is the government's flagship programme for helping homeowners switch from gas and oil boilers to low-carbon heating. Launched in April 2022 and significantly improved in October 2023, BUS provides substantial upfront grants that make heat pumps genuinely affordable for many households.
The scheme is designed to address the biggest barrier to heat pump adoption: the high upfront cost. While a gas boiler replacement might cost £2,500-£4,000, a heat pump typically runs £10,000-£16,000. The £7,500 BUS grant bridges much of that gap, making heat pumps a realistic option for ordinary households rather than just eco-enthusiasts with deep pockets.
Unlike some grants that involve complicated applications and means testing, BUS is refreshingly straightforward. If your property meets the criteria, you're eligible—regardless of income. Your installer handles all the paperwork, and you simply see a £7,500 reduction on your final invoice.
BUS Grant Amounts in 2025
| Technology | Grant Amount | Notes |
|---|---|---|
| Air source heat pump | £7,500 | Most common choice, suits majority of homes |
| Ground source heat pump | £7,500 | Higher total cost but better efficiency |
| Biomass boiler (rural areas only) | £5,000 | Must be off gas grid and in rural location |
The grant was increased from £5,000 to £7,500 in October 2023—an additional £2,500 that has significantly boosted uptake. Before the increase, around 3,000 vouchers were issued monthly. After the increase, applications rose to over 6,000 per month.
Real Homeowner Experiences
Sarah and Tom, Nottingham (1930s semi-detached): "We'd been putting off switching to a heat pump because of the cost. When the grant increased to £7,500, we finally took the plunge. Our total installation cost was £14,200 for a Vaillant Arotherm Plus—so we paid £6,700 after the BUS grant. That's not much more than a premium gas boiler would have cost. The house is actually warmer now than it was with the old boiler, and our energy bills are about £200 a year less. The process was straightforward: our installer handled everything with Ofgem, and the grant just came off our bill. No forms to fill in ourselves at all."
Margaret, Cardiff (1970s bungalow): "At 72, I wasn't sure I wanted the upheaval of switching to a heat pump. But my oil boiler was 18 years old and getting unreliable. The £7,500 grant made it affordable—my air source heat pump cost £11,500 total, so I paid £4,000. The installer was brilliant, explained everything clearly, and the system is so much easier than managing oil deliveries. My running costs are actually lower now, even with electricity being expensive. I wish I'd done it years ago."
James and Claire, Leeds (Edwardian semi): "Our house is EPC D, which just scraped in for the grant. The surveyor said we'd benefit from some additional insulation but it wasn't mandatory for BUS eligibility. We went for a Mitsubishi Ecodan at £13,800—so £6,300 after the grant. Installation took two days, and they had to upgrade three radiators to larger ones, which was included in the price. We're on the Octopus Cosy tariff now, which gives us cheap electricity for heat pump hours. Our annual heating cost is about the same as it was with gas, but we're not burning fossil fuels anymore. That matters to us."
David, Edinburgh (Victorian flat—Scotland note): "I was disappointed to find BUS doesn't apply in Scotland. However, Home Energy Scotland has its own scheme that gave us an interest-free loan plus a cashback grant of £7,500-£9,000 depending on circumstances. We ended up with a similar net cost to BUS. Worth checking the Scottish options if you're north of the border—they're actually quite generous."
Eligibility Requirements
Property Requirements
- Location: England or Wales only (Scotland has separate schemes through Home Energy Scotland)
- EPC rating: D or better at the time of application. If you're E, F, or G, you'll need to improve first (see below)
- No previous BUS funding: The property cannot have received a BUS grant before
- Existing building: New builds don't qualify—the scheme is for upgrading existing heating systems
- Owned or long leasehold: You must own the property or have a lease of at least 2 years remaining
System Requirements
- MCS-certified installer: Only MCS-registered contractors can apply for BUS vouchers
- MCS-certified equipment: The heat pump must be on the MCS product database
- Replaces fossil fuel heating: You must be switching from gas, oil, LPG, coal, or electric heating
- Proper sizing: The system must be designed following MCS heat loss calculations
What If Your EPC Is E, F, or G?
Don't panic if your current EPC isn't good enough. Many properties can be upgraded to D relatively cheaply:
- Loft insulation top-up: Getting to 270mm depth typically costs £300-£600 and often improves EPC by one band
- Cavity wall insulation: If your walls have unfilled cavities, this is often free through ECO4 or costs £500-£1,500 privately
- Draught-proofing: Sealing gaps around doors, windows, and floors can help move the EPC score
- Hot water cylinder insulation: If you have an uninsulated or poorly insulated cylinder, upgrading the jacket helps
Many heat pump installers can coordinate these improvements or recommend partners who can. Some offer package deals that include insulation upgrades.
Importantly, you can use ECO4 or the Great British Insulation Scheme for insulation improvements and still claim BUS for the heat pump—they're separate measures and don't conflict.
How to Apply for BUS
The good news is that you don't apply directly. Your MCS-certified installer handles the entire process. Here's what happens:
- Get an EPC (if needed): If you don't have a valid EPC or it's more than 10 years old, you'll need a new assessment. Cost: £60-£100. The assessor visits your home and produces the certificate, usually within a week.
- Improve to EPC D if necessary: If your EPC shows E, F, or G, address the recommended improvements before proceeding. Loft insulation and cavity wall insulation are usually the quickest wins.
- Get quotes from MCS installers: Contact 2-3 MCS-certified heat pump installers for quotes. They'll survey your property, calculate heat loss, and recommend appropriate equipment. Quotes should include all work needed, not just the heat pump unit.
- Choose an installer: Compare quotes carefully. The cheapest isn't always best—check reviews, ask about aftercare, and verify they're genuinely MCS-certified (not just claiming to be).
- Installer applies for voucher: Once you've accepted a quote, the installer applies for a BUS voucher through the Ofgem portal. This typically takes 1-2 weeks for approval.
- Installation completed: The voucher is valid for 3 months. Installation must be completed and signed off within this period. Most installations take 1-3 days depending on complexity.
- Grant paid to installer: After installation, the installer claims the grant from Ofgem. You simply see a £7,500 reduction on your final invoice. No money changes hands with you.
Typical Costs After BUS Grant
What will you actually pay out of pocket? Here's what homeowners are typically spending after the grant:
| System Type | Total Installed Cost | After £7,500 BUS Grant | Notes |
|---|---|---|---|
| Air source heat pump (compact, 5-7kW) | £9,000-£12,000 | £1,500-£4,500 | Small/medium homes, well-insulated |
| Air source heat pump (standard, 8-12kW) | £12,000-£16,000 | £4,500-£8,500 | Most common scenario |
| Air source heat pump (large, 14-16kW) | £15,000-£20,000 | £7,500-£12,500 | Large homes, higher demand |
| Ground source heat pump (horizontal) | £18,000-£28,000 | £10,500-£20,500 | Requires significant garden space |
| Ground source heat pump (borehole) | £25,000-£40,000 | £17,500-£32,500 | Highest efficiency, highest cost |
What's Included in These Prices?
A complete installation should include:
- Heat pump unit and controller
- Hot water cylinder (if not combi system)
- Installation labour and commissioning
- Pipework and connections
- Electrical work and wiring
- MCS certification and paperwork
- Any radiator upgrades needed (some installers include, others quote separately)
Be wary of quotes that seem surprisingly cheap—they may exclude essential work that gets added as extras later.
Running Cost Comparison
The upfront cost is only part of the picture. Heat pumps typically have lower running costs than gas boilers, especially if you're on a heat pump tariff:
| Heating System | Efficiency | Cost per kWh (fuel) | Effective Cost per kWh (heat) |
|---|---|---|---|
| Gas boiler (modern condensing) | 90% | 6.5p | 7.2p |
| Oil boiler | 85% | 7p | 8.2p |
| Air source heat pump (standard tariff) | 300% | 24p | 8.0p |
| Air source heat pump (heat pump tariff) | 300% | 10-15p | 3.3-5.0p |
Heat pump tariffs like Octopus Cosy, E.ON Next Heat Pump, and EDF GoElectric Heat offer electricity at 10-15p/kWh for heat pump operation. At these rates, heat pumps are significantly cheaper to run than gas.
The BUS Process Timeline
| Stage | Typical Duration | Notes |
|---|---|---|
| Get EPC (if needed) | 3-7 days | Book assessor, wait for visit, receive certificate |
| EPC improvements (if needed) | 1-4 weeks | Depends on work required |
| Get and compare quotes | 2-4 weeks | Multiple surveys, time to decide |
| Voucher application | 1-2 weeks | Installer handles via Ofgem portal |
| Scheduling installation | 2-8 weeks | Depends on installer availability |
| Installation | 1-3 days | Most done in 1-2 days |
| Total typical timeline | 6-16 weeks | Faster if EPC is already D or better |
Peak demand periods (typically spring and autumn) may have longer waits for installer availability. If you're planning ahead, booking during quieter winter months can mean faster installation.
Finding MCS-Certified Installers
Only MCS-certified installers can apply for BUS vouchers. Here's how to find reputable ones:
- MCS Installer Database: Visit mcscertified.com/find-an-installer and search by postcode
- Manufacturer Networks: Major brands like Mitsubishi, Daikin, and Vaillant have approved installer networks
- Energy Saving Trust: Their website links to vetted installers
- Which? Trusted Traders: Verified heating engineers with good track records
What to Check Before Signing
- MCS certification: Verify it's current (certificates expire annually)
- Reviews: Check Trustpilot, Google, and ask for references
- Insurance: Confirm they have adequate public liability and professional indemnity cover
- Quote detail: Everything should be itemised—beware vague lump sums
- Warranty: Heat pump manufacturers typically offer 5-7 year warranties; installer workmanship should be guaranteed too
- Aftercare: Who do you call if something goes wrong? Is there a service plan option?
Combining BUS with Other Support
BUS can work alongside other energy efficiency measures, though not with other grants for the same heat pump:
What You CAN Combine
- ECO4 for insulation: Get free loft or cavity wall insulation through ECO4, then use BUS for the heat pump
- Great British Insulation Scheme: Same principle—use for insulation improvements before the heat pump
- 0% VAT: Heat pumps already qualify for 0% VAT (until at least 2027), which applies on top of BUS
- Local authority grants: Some councils offer additional support that can stack with BUS
What You CANNOT Combine
- ECO4 for heat pump: You can't claim ECO4 and BUS for the same heat pump installation
- Previous BUS grant: A property can only receive one BUS grant ever
- Green Deal (legacy): Properties with outstanding Green Deal loans have complications
Frequently Asked Questions
Q: My house is listed—can I still get a heat pump and BUS?
A: Yes, though you may need listed building consent for the outdoor unit. Air source heat pumps in listed buildings often need careful siting and sometimes screening. Some listed building officers are more amenable than others—get advice early.
Q: I rent out my property. Am I eligible?
A: Yes, landlords can claim BUS for rental properties. However, the property must meet the EPC D requirement, and landlords should be aware of minimum energy efficiency standards (MEES) requirements for rentals.
Q: What happens if I sell the house before the heat pump has paid back?
A: The grant doesn't need to be repaid. You've legitimately claimed it for an eligible installation. Heat pumps can actually add value to properties, particularly as buyers become more energy-conscious.
Q: Can I install the heat pump myself and claim BUS?
A: No. BUS requires installation by an MCS-certified contractor. Self-install or installation by non-MCS engineers doesn't qualify.
Q: Is the £7,500 taxable?
A: No. BUS grants are not considered taxable income for homeowners. Landlords should consult an accountant about their specific tax situation.
Q: What if my voucher expires before installation?
A: Vouchers are valid for 3 months. If installation genuinely can't be completed in time (for reasons beyond your control), installers can request an extension through Ofgem. But it's better to ensure realistic scheduling from the start.
Q: Will the scheme definitely run until 2028?
A: The scheme is currently funded until March 2028. However, government policy can change. If you're eligible and interested, applying sooner rather than later locks in the current grant level and avoids any risk of scheme changes.
Q: Are hybrid heat pumps eligible?
A: Yes, hybrid systems (heat pump with gas/oil boiler backup) can qualify for BUS. However, the heat pump component must meet MCS standards and be properly sized. Some installers prefer full heat pump installations; others specialise in hybrids.
Scotland and Northern Ireland
Scotland
BUS doesn't apply in Scotland, but equivalent support is available through Home Energy Scotland:
- Interest-free loans up to £7,500 for heat pumps
- Cashback grants of £7,500-£9,000 for eligible households
- Additional rural uplift for remote properties
Contact Home Energy Scotland (0808 808 2282) for personalised advice. Their scheme can be more generous than BUS for some households.
Northern Ireland
Northern Ireland has its own schemes through the Northern Ireland Sustainable Energy Programme (NISEP) and various council grants. The availability and generosity of support varies. Check NI Energy Advice for current options.
The Bottom Line
The Boiler Upgrade Scheme has transformed the economics of heat pump installation in England and Wales. With a £7,500 grant, even premium installations become comparable in cost to high-end gas boiler replacements—while delivering lower running costs and zero direct carbon emissions.
The application process is straightforward: find an MCS-certified installer, let them handle the paperwork, and see the grant deducted from your invoice. You never need to apply directly or handle grant money yourself.
If your EPC is D or better (or can be improved to D with modest upgrades), you're eligible regardless of income. The scheme runs until 2028, but demand is increasing and installer availability can be limited during busy periods.
For homeowners considering the switch, the message is clear: the financial case for heat pumps has never been stronger. The combination of BUS grants, 0% VAT, and heat pump electricity tariffs means that many households can now upgrade to low-carbon heating for little more than they'd spend on a gas boiler replacement—while enjoying lower running costs for years to come.
Get quotes, compare carefully, and take advantage of the £7,500 while it's available. Your future self—and the planet—will thank you.