The regulations governing the Boiler Upgrade Scheme (BUS) in England and Wales were amended in May 2024 by the Boiler Upgrade Scheme (England and Wales) (Amendment) Regulations 20241. Ofgem, which administers the scheme, states the amendment in the compliance footnote of its quarterly reports, which are published under Regulation 30(3) of the Boiler Upgrade Scheme (England and Wales) Regulations 20221.
The scheme launched on 23 May 2022 and provides upfront grants towards low carbon heating, paid to the installer rather than the householder and reflected in the quote and invoice1. Ofgem's property owner guidance lists the grant levels as £7,500 for air-to-water heat pumps and ground source heat pumps, £2,500 for air-to-air heat pumps and £5,000 for biomass boilers5. Grant levels for air source and ground source heat pumps rose from £5,000 and £6,000 to £7,500 on 23 October 20233.
"The regulations were amended in May 2024 - The Boiler Upgrade Scheme (England and Wales) (Amendment) Regulations 2024"
Budget figures reported by Ofgem have been revised between reports. Issue 10, published 29 November 2024, records £50,059,000 allocated from the £150 million Year 1 budget and £88,671,500 from the £150 million Year 2 budget1. Issue 12, published 30 May 2025, gives the same two years as £50,039,000 and £88,455,5003. Issue 15, published 27 February 2026, gives £50,009,000 and £88,410,5002. Ofgem notes that unspent budget is not carried over between scheme years1.
| Scheme year | Budget allocation | Budget spent | Remaining |
|---|---|---|---|
| Year 1 (May 2022 to Mar 2023) | £150,000,000 | £50,009,000 | £99,991,000 |
| Year 2 (Apr 2023 to Mar 2024) | £150,000,000 | £88,410,500 | £61,589,500 |
| Year 3 (Apr 2024 to Mar 2025) | £280,000,000 | £188,845,000 | £91,155,000 |
| Year 4 (Apr 2025 to Mar 2026) | £295,000,000 | £244,337,500 | £50,662,500 |
Source: Ofgem Quarterly Report Issue 152
Year 3 funding was increased twice: by £30 million announced in November 2024 and a further £25 million announced on 30 January 2025, taking the Year 3 budget from £150 million to £205 million, with permission to over-allocate vouchers up to £280 million2. Issue 10, written before the January 2025 increase, describes the Year 3 budget as £180 million with over-allocation to £250 million1.
Cumulative figures also differ by report. Issue 15 records 114,022 voucher applications received and 80,467 vouchers issued, worth £563,012,000, with 75,174 grants paid worth £523,357,0002. Of those grants, 73,333 (97.6 per cent) were for air source heat pumps, 1,424 (1.9 per cent) for ground source heat pumps, 381 (0.5 per cent) for biomass boilers and 36 (0.05 per cent) for shared ground loop ground source heat pumps2.
Why it matters for households
The amendment regulations are the legal basis on which BUS applications are assessed, so the version in force at the date an application is properly made determines the rules that apply to it5. Ofgem's draft property owner guidance V5 states that changes coming into force on 28 April 2026 apply to applications properly made on or after that date, and that earlier applications fall under version 4.1 of the guidance5. The guidance sets out eligibility limits that bear on a home's move away from fossil fuel heating: a property will usually not be eligible if public funding has already been received for a low carbon heating system at the same address, social housing is not eligible, new-build properties are generally not eligible except certain self-builds, and a fossil fuel heating system cannot be kept alongside a BUS-funded installation5. Vouchers are valid for three months for air-to-water heat pumps, air-to-air heat pumps and biomass boilers, and six months for ground source heat pumps5. Ofgem also notes that around 10 per cent of air source heat pump and biomass vouchers expired in earlier quarters1.
What happens next
Ofgem's draft property owner guidance V5 is dated 25 March 2026 and states the amended regulations come into force on 28 April 20265. Ofgem publishes a monthly scheme update, a fortnightly budget overview and an annual report by 31 July each year1. The Department for Energy Security and Net Zero publishes monthly BUS statistics1.
Sources5 cited
- Quarterly Report – Issue 10, ofgem.gov.uk
- Boiler Upgrade Scheme Quarterly Report Issue 15, ofgem.gov.uk
- Quarterly Report – Issue 12, ofgem.gov.uk
- Quarterly Report – Issue 9, ofgem.gov.uk
- Boiler Upgrade Scheme: Property owner guidance V4, ofgem.gov.uk