The Boiler Upgrade Scheme grant is worth £7,500 towards an air source or ground source heat pump, rising to £9,000 until 31 March 2027 if your home is off the gas grid and you are replacing oil or LPG heating. You apply for it through your installer, not directly to the government, with the discount taken off your quote before you pay a penny.
What is the Boiler Upgrade Scheme?
The Boiler Upgrade Scheme (BUS) is a government capital grant, funded by the Department for Energy Security and Net Zero and administered day-to-day by Ofgem. It exists to close the price gap between a heat pump and a like-for-like gas boiler replacement, and it’s been running since May 2022 with funding confirmed through to 2028.
The mechanism is straightforward but often misunderstood. You don’t fill in a form yourself, and you don’t get a cheque in the post. An MCS-certified installer applies to Ofgem on your behalf once your quote is agreed, Ofgem issues a voucher, and the installer knocks that amount straight off your final invoice. From your side, the grant simply appears as a discount.
At HomeKOG we handle the entire BUS application as standard on every eligible heat pump install we quote. It’s built into the process, not an optional extra you need to chase.
How much is the Boiler Upgrade Scheme grant worth?
The grant is worth £7,500 for most eligible homes, rising to £9,000 for off-gas-grid properties replacing oil or LPG heating. Air-to-air heat pumps get a separate, lower grant of £2,500.
| Heating system installed | Standard grant | Enhanced off-gas-grid rate (replacing oil or LPG) | Enhanced rate window |
|---|---|---|---|
| Air source heat pump (air-to-water) | £7,500 | £9,000 | 21 July 2026 – 31 March 2027 |
| Ground source heat pump | £7,500 | £9,000 | 21 July 2026 – 31 March 2027 |
| Air-to-air heat pump | £2,500 | £2,500 (no enhanced rate) | Eligible from 21 July 2026 |
| Biomass boiler (rural off-grid only) | £5,000 | £5,000 | No change |
The £9,000 enhanced rate is a temporary top-up aimed at homes that would otherwise be paying to run oil or LPG heating with no mains gas connection to fall back on. Off-grid homes replacing electric, coal or other heating still get the standard £7,500. These properties tend to see the biggest running-cost improvement from switching, so the extra £1,500 is there to remove more of the upfront barrier. It’s due to end on 31 March 2027 unless the government extends it again, so if you’re off-grid and eligible, there’s a real financial case for not leaving it too late.
One grant is issued per property, and it can only be used once. It can’t be combined with certain other government heating grants on the same installation (for example, ECO4 funding for the same measure), so your installer will confirm which route makes sense for your circumstances before applying.
Who qualifies for the Boiler Upgrade Scheme?
You qualify for BUS if you own an England or Wales property, are replacing a qualifying fossil fuel or non-heat-pump electric heating system with an air or ground source heat pump, and use an MCS-certified installer. Eligibility comes down to the property, the person, and the installer, and all three need to be right.
| Requirement | Detail |
|---|---|
| Ownership | You must own the property (owner-occupier or landlord), or be a small business applying for a heat pump at a commercial premises. |
| Location | Property must be in England or Wales. BUS does not cover Scotland or Northern Ireland (see below). |
| Existing heating | You must currently have a fossil fuel system (mains gas, oil, or LPG boiler) or an electric heating system that isn’t already a heat pump. You can’t claim BUS to replace one heat pump with another. |
| System type | Air source (air-to-water) or ground source heat pump connected to a wet central heating system (radiators or underfloor heating). Air-to-air heat pumps qualify for a lower £2,500 grant if they fully replace your existing heating. |
| Installer | Must be MCS-certified for heat pump installation and a member of an approved consumer protection code, such as HIES or RECC. |
| Property type | Domestic and small non-domestic buildings, including new self-build properties in some cases. Your installer will confirm your specific case. |
| Prior grants | The property hasn’t already received a BUS grant. |
Two points worth flagging clearly. First, insulation is not a mandatory eligibility condition. You don’t need loft or cavity wall insulation in place to qualify for the grant. That said, a properly certified installer will still assess your home’s heat loss and flag where insulation upgrades would let a smaller, cheaper heat pump do the job more efficiently; it’s good practice, not a grant requirement. Second, this is an England and Wales scheme only. Scotland runs its own support through Home Energy Scotland, and Northern Ireland has separate arrangements via its own energy efficiency schemes. If you’re outside England or Wales, ask about the equivalent local scheme rather than BUS.
Which parts of the UK does the Boiler Upgrade Scheme cover?
- England: Boiler Upgrade Scheme applies, administered by Ofgem.
- Wales: Boiler Upgrade Scheme applies, same rates and process as England.
- Scotland: Not covered by BUS; separate funding runs through Home Energy Scotland grants and loans.
- Northern Ireland: Not covered by BUS; check current NI-specific heating support.
How do you apply for the Boiler Upgrade Scheme grant?
Your installer applies for you, in six steps from initial survey to redeemed voucher. The process is designed so the paperwork sits with them, not the homeowner.
- Get a survey and quote. An MCS-certified installer assesses your property (heat loss, radiator sizing, hot water demand) and provides a fixed quote that already shows the BUS grant deducted.
- You accept the quote. Once you sign off and the installation date is set, the installer prepares the BUS application on your behalf, using details from the survey and your property’s MCS-compliant design.
- Installer submits to Ofgem. The application goes through the Ofgem BUS portal, referencing the installer’s MCS certification number and the technical specification of the system being fitted.
- Ofgem reviews and issues a voucher. Ofgem checks the application against eligibility rules and, if approved, issues a grant voucher that’s valid for a set period (generally around three months) to allow time for installation.
- Installation goes ahead. The heat pump is fitted as specified in the application. The system installed must match what was approved. Swapping specifications after approval can jeopardise the grant.
- Grant redeemed, invoice adjusted. Once installation is complete and confirmed to Ofgem, the installer redeems the voucher and the grant amount is already reflected in what you’ve paid. You’re never asked to pay the full amount upfront and claim it back.
How long does the Boiler Upgrade Scheme process take?
From survey to installed heat pump typically takes a matter of weeks rather than months, though timelines vary with Ofgem’s processing volumes. As a general guide:
| Stage | Typical timescale |
|---|---|
| Survey to quote | Same visit to a few days |
| Application submission to Ofgem approval | Usually a small number of weeks |
| Voucher validity window | Around 3 months from issue |
| Installation once approved | Typically 1–3 days on-site for the heat pump itself |
Because the voucher has a shelf life, it’s worth having your installer booked in and ready to go before the application is submitted, rather than applying speculatively months ahead of when you actually want the work done.
What doesn’t the Boiler Upgrade Scheme grant cover?
BUS doesn’t cover the full cost of your heat pump, unrelated renovation work, or ongoing running costs. It’s a contribution, not a full funding package, and it’s worth being clear-eyed about its limits.
- The full system cost. A typical air source heat pump installation runs well beyond the £7,500–£9,000 grant, so you’ll still be paying the balance. The grant reduces the bill; it doesn’t eliminate it.
- Most of the cost of an air-to-air system. Since 21 July 2026 air-to-air heat pumps get £2,500 rather than £7,500, and only when they fully replace the existing heating system rather than being added alongside it.
- Extensive radiator or pipework replacement beyond what’s needed. Some radiator upgrades are a normal part of a heat pump install and get factored into the overall project cost, but the grant itself is a fixed sum toward the heat pump system. It’s not a blank cheque for wider renovation work.
- Ongoing running costs, servicing or maintenance. BUS is a one-off installation grant, not a contribution to electricity bills or annual servicing.
- A second claim on the same property. One grant per property, once.
Why do Boiler Upgrade Scheme applications get rejected or delayed?
Most rejections and delays trace back to installer certification issues, a mismatch between what was approved and what’s installed, or a voucher expiring before work is finished. These problems are avoidable and tend to come from the same handful of causes:
- Installer not MCS-certified for the specific work, or their certification has lapsed at the point of application.
- Existing heating system doesn’t meet the criteria: for instance, the property already has a heat pump, or the “existing system” being replaced doesn’t count as a qualifying fossil fuel or non-heat-pump electric system.
- Mismatch between what was approved and what’s installed. If the specification changes mid-project (a different model, capacity, or system type) without updating Ofgem, it can hold up or invalidate the voucher.
- Property details don’t match records, such as address discrepancies between the application and official property data.
- Voucher expires before installation is completed, usually because of scheduling delays after approval. That’s another reason to have your installer and timeline confirmed before applying.
- Incomplete documentation at submission, such as missing survey data or an incomplete MCS design.
A competent installer who applies for BUS applications routinely will have seen most of these issues before and structure the paperwork to avoid them. It’s one of the practical reasons to check an installer’s BUS track record, not just their heat pump credentials, before committing.
Can you combine the Boiler Upgrade Scheme grant with 0% VAT?
Yes, BUS and 0% VAT on heat pump installations apply together automatically, with no extra paperwork on your part. Heat pump installations, including materials and labour, currently qualify for 0% VAT, rather than the standard rate. This is a separate relief from BUS and applies automatically to the invoice; you don’t need to apply for it separately.
In practice, that means two savings stack on top of each other: the BUS grant reduces the headline cost of the system, and 0% VAT means there’s no VAT added to what’s left. For a typical installation, the combined effect is a meaningfully lower final price than the same job would have cost a few years ago, before either measure existed.
Worth noting: the 0% VAT rate is under periodic government review and isn’t guaranteed indefinitely, so it’s another factor, alongside the enhanced off-grid grant rate, that makes near-term timing relevant if you’re already leaning toward a heat pump.
What do you need to have ready before getting a heat pump quote?
Have proof of ownership, details of your current heating system, and your property’s approximate size and insulation levels ready before an installer visits. You’ll get a faster, more accurate quote, and a smoother BUS application, if you can answer these:
- Proof of ownership (or landlord status), since BUS requires this to be confirmed as part of the application.
- Details of your current heating system: fuel type, boiler age, and whether you’re on or off the gas grid.
- Approximate property size and current insulation levels (loft, cavity or solid wall, glazing type). This speeds up the heat loss survey, even though it’s not an eligibility requirement.
- Any existing radiators or underfloor heating layout, or at least an idea of how many rooms and radiators are involved.
- Where you’d want an outdoor unit sited, if you already have a preference: garden space, side return, or similar.
- Your energy bills or usage, if available, to help the installer size the system accurately.
None of this needs to be exact (a proper MCS survey will confirm the detail), but arriving with the basics means your installer can move straight to a firm, grant-adjusted quote rather than a rough estimate that changes later.
If you’re weighing up whether a heat pump makes sense for your property, the combination of the BUS grant, 0% VAT, and lower running costs than a fossil fuel system is generally where the numbers start to work in the homeowner’s favour, particularly for oil and LPG homes eligible for the enhanced £9,000 rate before it ends in March 2027. Get a survey done, see the grant-adjusted figure in writing, and you’ll have a clear basis for the decision either way.
