The Boiler Upgrade Scheme (BUS) is the UK government’s main financial incentive to help homeowners in England and Wales replace fossil-fuel heating systems with low-carbon alternatives. As of 2026 the grant values are:
- Air source heat pump (ASHP): £7,500
- Ground source heat pump (GSHP) or water source heat pump: £7,500
- Biomass boiler (limited eligibility): £5,000
These grants are deducted at point of purchase — you never receive cash directly. Your MCS-certified installer claims the voucher from Ofgem on your behalf and discounts it from the invoice.
Who Is Eligible
| Requirement | Detail |
|---|---|
| Property type | Owner-occupied or private rented in England or Wales |
| Existing heating | Must be replacing a fossil fuel system (gas, oil, LPG, electric storage heaters) |
| EPC requirement | Property must have a valid EPC with no outstanding loft or cavity insulation recommendations* |
| Installer | Must use an MCS-accredited contractor |
| Grant per property | One grant per property (some exceptions for properties that already claimed under an earlier round) |
*If your EPC recommends loft or cavity insulation, you do not automatically lose eligibility — but you must either complete those measures first or obtain a written exception from an energy assessor.
The scheme does not apply to new-build homes (which should already meet higher energy standards) or social housing (covered by separate programmes such as the Social Housing Decarbonisation Fund).
How to Apply
- Get an EPC if you do not already have a valid one (£60–£120 from an accredited assessor).
- Obtain quotes from at least two MCS-accredited installers. Use the MCS installer finder at mcscertified.com.
- Choose your installer and confirm the work qualifies for BUS.
- The installer creates a voucher application on the Ofgem portal before work begins. You will receive a voucher confirmation email; the voucher is valid for three months.
- Work is completed and the installer redeems the voucher, deducting £7,500 from your invoice.
- You pay the net cost (total installed price minus £7,500) and the installer handles all paperwork with Ofgem.
There is no income test. The BUS is open to all owner-occupiers regardless of household income, making it different from means-tested schemes such as the ECO4 obligation.
Typical Installed Costs After the Grant
| System | Gross Installed Cost | BUS Grant | Typical Net Cost |
|---|---|---|---|
| Air source heat pump (ASHP) | £10,000–£18,000 | £7,500 | £2,500–£10,500 |
| Ground source heat pump (GSHP) | £18,000–£35,000 | £7,500 | £10,500–£27,500 |
| Biomass boiler | £12,000–£22,000 | £5,000 | £7,000–£17,000 |
Costs vary with property size, installer region, and whether existing pipework and radiators need upgrading. Heat pumps typically require either underfloor heating or oversized radiators to work efficiently. Budget £1,000–£4,000 extra if you need to upgrade radiators throughout.
Running Costs After Installation
Heat pump running costs depend heavily on your electricity tariff. At a typical 2026 residential rate of around 24–28 p/kWh and a SCOP of 3.0, the effective heat cost is roughly 8–9 p/kWh — comparable to or slightly above gas at current rates. Households that switch to an EV tariff with off-peak overnight rates (commonly 7–10 p/kWh) can reduce their heat pump running costs substantially by pre-heating the home at night.
The Heat Pump Ready programme and Ofgem’s smart tariff work are expected to improve the economics further through 2027.
Other Heating Grants Available in 2026
ECO4 (Energy Company Obligation)
Funded by energy suppliers and targeted at low-income households and those in fuel poverty. ECO4 can fund:
- Loft and cavity wall insulation
- Solid wall insulation
- First-time central heating
- Heat pump installations in eligible properties
To check eligibility, use the Ofgem ECO4 eligibility checker or contact your energy supplier directly. There is no application fee.
Great British Insulation Scheme (GBIS)
A separate Ofgem-administered programme funding single insulation measures (typically loft or cavity wall) for homes rated EPC D–G. Not exclusively for heating systems but can make a heat pump installation more viable by improving the building fabric first.
Warm Home Discount
A £150 rebate applied directly to electricity bills for eligible low-income households. Qualifying households are identified automatically by the DWP/energy suppliers from April each year; you do not need to apply.
Home Upgrade Grant (HUG2)
Delivered by local authorities in England for off-gas-grid homes that are EPC E, F, or G. Can fund insulation and low-carbon heating together. Contact your local council to check if your area is participating.
Wales: Nest and Arbed
The Nest scheme (managed by Warm Wales) provides free energy efficiency improvements to eligible homeowners and private renters in Wales. Arbed is the area-based scheme for community energy improvements. Both target low-income and fuel-poor households.
Scotland: Warmer Homes Scotland
Scottish Government programme providing free energy efficiency improvements and heating systems to low-income households. Delivered by Home Energy Scotland; call 0808 808 2282 to check eligibility.
Stacking Multiple Grants
You can combine BUS with other grants in some cases. For example:
- BUS grant for the heat pump + ECO4 insulation (if income-eligible) = significant combined support
- BUS + local council Sustainable Warmth grant = possible for off-gas-grid properties
Always confirm with your installer and the relevant scheme administrator before assuming grants can be combined. Some schemes prohibit double-funding of the same measure.
[!warning] Voucher Expiry A BUS voucher is valid for three months from issue. If the installation is delayed (supply chain, planning issues), ask your installer to apply for a reissue before expiry — Ofgem does allow extensions in some circumstances.
What to Ask Your Installer
- Are you MCS accredited for heat pump installations?
- Will my existing radiators and pipework be suitable, or will they need upgrading?
- What SCOP rating do you design to, and can I see the MCS heat loss calculation?
- Will the system work with my current hot water cylinder, or do I need a new one?
- Do you handle the BUS voucher application, and when will you submit it?
A reputable installer will provide a full MCS Microgeneration Installation Standard (MIS) compliant heat loss calculation before quoting, showing that the heat pump is correctly sized for your home.
