The Boiler Upgrade Scheme (BUS) changed on 28 April 2026, when amended regulations came into force1. The changes expanded eligibility for multi-technology installations, introduced £2,500 grants for air-to-air heat pumps (AAHPs), relaxed the requirement for a valid EPC, required installers to deduct the BUS grant from upfront costs, and made the Microgeneration Certification Scheme (MCS) the sole certification scheme3. The Department for Energy Security and Net Zero (DESNZ) amended the regulations, which were laid in Parliament on 25 March 20264.
The scheme is administered by Ofgem and is installer-led: the installer submits a voucher application on behalf of the property owner, who must give consent3. To be eligible, all BUS installations must be MCS certified3. Ofgem states that installers are required to pass on the full value of the BUS grant as an upfront discount to the property owner1.
Current grant values are set out in the scheme statistics3:
| Technology | Grant |
|---|---|
| Air-to-water heat pump | £7,500 |
| Ground source heat pump (including water source and shared ground loops) | £7,500 |
| Air-to-air heat pump | £2,500 |
| Biomass boiler | £5,000 |
| Air-to-water or ground source heat pump, eligible off-gas grid properties heated by LPG or oil | £9,000 |
The £9,000 uplifted grant for eligible off-gas grid properties applies to applications properly made on or after 21 July 2026 and remains available until 31 March 20271. Ofgem's annual report says the grant increased from £7,500 to £9,000 for eligible properties not connected to the gas grid from that date4. The £2,500 AAHP grant is for residential properties only1. Exhaust air-to-water heat pumps became eligible for the £7,500 grant from 28 April 20261. From the same date, BUS heat pumps can be installed alongside supplementary heating appliances, provided those appliances are not fossil fuel based1.
Vouchers for air-to-water heat pumps, air-to-air heat pumps and biomass boilers are valid for three months; ground source heat pump vouchers are valid for six months3. Vouchers are issued first come, first served until the budget cap for the financial year is reached3. The scheme is in its fifth year, with a budget of £400 million for 2026/27, and the government confirmed funding for further years up to 2029/30 through the Warm Homes Plan in January 20263. Across the first four years, over £560 million was paid out through grants3. Ofgem reports 80,098 vouchers redeemed from launch to the end of March 2026, with £560.3 million paid, and 1,789 MCS certified installation companies registered at that point4.
"From 28 April 2026, properties are no longer required to have a valid EPC to apply for BUS."
Why it matters for households
The EPC change removes a documentation barrier that previously sat in front of applications, and the AAHP grant opens the scheme to homes without a wet central heating system, since air-to-air systems do not require new pipework or radiators5. Air-to-air heat pumps typically do not provide domestic hot water, which is a key distinction from air-to-water systems5. The requirement that installers deduct the grant from upfront costs changes the cash flow: the price paid by the property owner is the total cost of the installation less the value of the grant3. MCS certification is now the single route to eligibility, so the certification status of the installing company is central to whether a grant can be claimed at all3. For a home's energy independence, the scheme reduces the capital cost of moving away from fossil fuel heating, though the grant covers part of the installation cost only and the sources do not state what proportion of a typical bill or installation it represents.
What happens next
The final date on which Ofgem can issue vouchers is 31 December 20291. The £9,000 off-gas grid uplift runs until 31 March 20271. Statistics on AAHP uptake will be incorporated into the DESNZ release once the first grants have been paid3. MCS has redeveloped its installer scheme, which will be rolled out throughout 2026 and into early 20272. In June 2026, MCS:2025 was approved by the Secretary of State as a consumer code for BUS4.
Sources5 cited
- Boiler Upgrade Scheme Installer Guidance V5.1, ofgem.gov.uk
- Boiler Upgrade Scheme Installer Guidance, ofgem.gov.uk
- [](https://assets.publishing.service.gov.uk/media/6a855be254bcee010d5144fa/Boiler_Upgrade_Scheme_BUS_Statistics_July_2026.xlsx), assets.publishing.service.gov.uk
- BUS Annual Report 2025 to 2026, ofgem.gov.uk
- New £2,500 air-to-air heat pump grant explained, fuseenergy.com