What happens if my heat pump installation quote is higher than the £7,500 Boiler Upgrade Scheme grant in 2025?

The Problem Statement

Picture this: you’ve finally decided to future-proof your home with a low-carbon heat pump, spurred on by the government’s £7,500 Boiler Upgrade Scheme (BUS) grant. You’ve done your research, compared installers, and are ready to take the plunge. Then the quote lands in your inbox—and it’s £10,500. That’s £3,000 more than the grant covers. Suddenly, your eco-friendly upgrade feels out of reach.

This scenario is playing out in homes across the UK. According to recent industry data, the average air source heat pump installation in 2025 ranges from £8,500 to £13,000, depending on property size, insulation, and regional labour costs. For many, the grant is generous but not enough to cover the full bill. With energy prices still volatile and the government pushing for net zero, the pressure to upgrade is real—but so is the financial gap.

Homeowners and landlords are left asking: What are my options if my quote is higher than the grant? Can I still proceed? Are there hidden costs or extra funding routes? And how do I avoid nasty surprises or delays?

This guide provides clear, evidence-based answers—so you can make confident decisions, avoid common pitfalls, and maximise your investment in a warmer, greener home.

The Complete Breakdown

The Boiler Upgrade Scheme (BUS) is designed to help homeowners and private landlords in England and Wales replace fossil fuel heating systems with low-carbon alternatives like heat pumps. In 2025, the grant covers up to £7,500 towards the cost of an eligible air source or ground source heat pump installation. But what happens if your quote is higher?

The grant is a fixed contribution—not a cap on total cost. If your installer quotes £10,500, the grant covers £7,500, and you’re responsible for the remaining £3,000 out of pocket.^[5]
Typical installation costs for air source heat pumps in 2025 range from £8,500–£13,000, depending on property size, insulation, and system complexity.^[5]
Ground source heat pumps are even pricier, often exceeding £15,000–£20,000, so the shortfall can be significant.
Additional works—such as upgrading radiators, electrical supply, or insulation—are not covered by the grant and can add hundreds or thousands to your bill.
Eligibility requirements include a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation, and the property must be replacing a fossil fuel system.^[2]

Historically, government grants like ECO4 and the Affordable Warmth Scheme have targeted low-income or vulnerable households, but the BUS is open to a wider range of homeowners and landlords—though social housing and most new-builds are excluded.^[1][2][3]

Key point: If your quote exceeds the grant, you must fund the difference yourself, unless you can access additional support (see below).

“Don’t be put off by a higher quote—there are ways to bridge the gap, but it pays to plan ahead and get multiple quotes from TrustMark-registered installers.”

The Money Trail: Costs and Savings Breakdown

Let’s break down the real numbers behind heat pump installations and the BUS grant in 2025:

System Type	Typical Installation Cost	BUS Grant	Typical Shortfall
Air Source Heat Pump	£8,500–£13,000	£7,500	£1,000–£5,500
Ground Source Heat Pump	£15,000–£20,000+	£7,500	£7,500–£12,500+

Additional costs may include electrical upgrades (£300–£1,200), radiator replacements (£500–£2,000), or insulation improvements (varies).
Regional variations: London and the South East tend to have higher labour and material costs, while some rural areas may face extra charges for access or logistics.
Long-term savings: A well-installed heat pump can reduce annual heating bills by £300–£700 compared to older oil or LPG systems, but savings depend on electricity tariffs and home insulation.
Payback period: With the BUS grant, typical payback is 8–15 years, but this varies by property and energy use.

If you’re facing a funding shortfall, consider:

Using savings or low-interest loans (some councils offer green home loans)
Combining with other grants (e.g., ECO4 for insulation, if eligible)^[1][3]
Negotiating with installers for phased works or value engineering
Checking for local authority top-ups or regional schemes

Before committing, use our Eligibility checker to see what support you might access.

Real Stories from the Field

To bring this issue to life, here are three anonymised but realistic case studies from across the UK:

Manchester: Victorian Terrace, Family of Four

Sarah and Tom received a quote of £11,200 for an air source heat pump. The BUS grant covered £7,500, leaving a £3,700 gap. By combining the grant with a council-backed green home loan and using ECO4 for loft insulation, they reduced their upfront cost to £1,800. Their annual heating bill dropped by £500, and their EPC rating improved from E to C.

Glasgow: 1960s Flat, Pensioner Couple

James and Margaret’s quote was £9,000. The BUS grant left them with £1,500 to pay. They struggled to find extra funding but negotiated a payment plan with their installer. Their new heat pump is quieter and more efficient, and they qualified for the winter fuel payment due to improved energy efficiency.

Norfolk: Rural Detached, Self-Employed Owner

Alex’s ground source heat pump quote was £18,500—well above the grant. With no ECO4 eligibility, he used savings and a low-interest green mortgage to cover the £11,000 shortfall. The system slashed his oil bills by £800 a year, and he expects to recoup the investment over 12–14 years.

These stories show that while the BUS grant is a major help, most homeowners will need to plan for additional costs. Each journey is unique—use our How the scheme works guide for step-by-step support.

Future-Proofing Your Decision

With the UK government committed to net zero by 2050, heat pumps are set to play a central role in home heating. Here’s what to consider for the long term:

Grant levels may change: The BUS grant has already increased from £5,000 to £7,500, but future funding is not guaranteed. Acting sooner may secure the best deal.^[5]
Energy prices are unpredictable: Electricity tariffs could rise or fall, affecting your payback period. Investing in insulation and smart controls can maximise savings.
Resale value: Homes with modern, low-carbon heating may command a premium as buyers seek energy efficiency and lower running costs.
Policy shifts: New regulations may require landlords or sellers to meet higher EPC ratings, making early upgrades a smart move.
Technology advances: Heat pumps are becoming more efficient and affordable each year. If you’re not ready now, keep an eye on market trends and revisit your options annually.

Ready to take the next step? Check your eligibility and apply for the Boiler Upgrade Scheme today.

Frequently Asked Questions

What if my installer’s quote is more than the £7,500 BUS grant?

The BUS grant is a fixed contribution. If your quote is higher, you must pay the difference yourself. Some homeowners use savings, loans, or combine grants to cover the shortfall.^[5]

Can I combine the BUS grant with ECO4 or other schemes?

You cannot use multiple public funds for the same installation, but you may combine BUS with ECO4 or LA Flex for separate measures (e.g., insulation). Check eligibility for each scheme.^[2][3]

Are there hidden costs not covered by the grant?

Yes. Upgrades to radiators, electrical supply, or insulation are not covered by the BUS grant and can add to your total bill. Always request a detailed quote from your installer.^[5]

What if I can’t afford the shortfall?

Some councils offer green home loans or top-ups. You can also explore low-interest loans, payment plans, or seek advice from energy charities. Use our Eligibility checker for tailored options.

Does the grant cover ground source heat pumps?

Yes, but ground source systems are usually much more expensive than air source. The grant is still capped at £7,500, so expect a larger shortfall.^[5]

Can I get a heat pump grant for a new-build property?

Most new-builds are excluded from the BUS grant unless it’s a self-build never owned by a business or organisation.^[2]

What EPC rating do I need?

Your property must have a valid EPC with no outstanding recommendations for loft or cavity wall insulation. If upgrades are needed, complete them before applying.^[2]

How do I avoid overpaying for installation?

Get at least three quotes from TrustMark-registered installers, compare breakdowns, and ask about all potential extras. Don’t be afraid to negotiate.

What happens if my application is delayed?

Delays can occur due to paperwork errors, installer backlogs, or missing documentation. Prepare your documents early and follow up regularly with your installer and grant administrator.

Can landlords apply for the BUS grant?

Yes, private landlords can apply for eligible properties. Social housing and council-owned properties are not eligible.^[2]

Is the BUS grant available in Scotland or Northern Ireland?

No, the BUS grant is for England and Wales only. Scotland and Northern Ireland have separate schemes—check local authority websites for details.^[2]

Will the grant amount change in future?

Grant levels are reviewed periodically and could change. The current £7,500 rate is confirmed for 2025, but future funding is not guaranteed.^[5]

Can I apply if I’ve already started installation?

No. The installation must not be commissioned before the grant application is approved.^[2]

How long does the process take?

From application to installation, expect 1–3 months, depending on installer availability and paperwork. Delays are possible during busy periods.^[5]

Where can I get help with my application?

Visit How the scheme works or contact our team for free, expert guidance at every stage.

What Happens If My Heat Pump Installation Quote Exceeds the £7,500 Boiler Upgrade Scheme Grant in 2025?