How Much Is the Boiler Upgrade Scheme Grant and How Long Is the Wait?
The Boiler Upgrade Scheme (BUS) offers a flat £7,500 grant toward an air source or ground source heat pump in England and Wales, applied for by your MCS-certified installer, with current survey-to-installation waiting times running 8–16 weeks depending on regional installer capacity. Version 5 of the scheme guidance, in force from 28 April 2026, extended funding through to 2029/30, giving homeowners more certainty than the year-to-year renewal uncertainty of earlier phases.
Grant Criteria: Who Qualifies
- Property type: Domestic properties in England and Wales with an existing fossil fuel heating system (oil, LPG, or mains gas boiler) being replaced.
- Standard grant: £7,500 flat rate for both air source heat pumps (ASHP) and ground source/water source heat pumps (GSHP) — GSHP installs cost significantly more but receive the same grant amount.
- New: air-to-air heat pumps are now eligible for £2,500, added under the Version 5 guidance update.
- New: enhanced £9,000 grant for air source or ground source heat pumps at eligible off-gas-grid oil or LPG properties, running 21 July 2026 to 31 March 2027 — aimed at the roughly 865,000 English and Welsh homes currently heating with oil or LPG.
- Biomass boilers: still supported at £5,000, contrary to some outdated guides claiming this was withdrawn — the property must be off the gas grid, in a rural location, and the boiler must have the correct emissions certificate.
- EPC requirement removed: the previous rule requiring a valid EPC with no outstanding loft or cavity wall insulation recommendations was dropped under Version 5 guidance — an EPC flagging insulation work no longer blocks your grant.
- Installer requirement: must be fitted by an installer certified under the Microgeneration Certification Scheme (MCS) — the grant is claimed by the installer on your behalf and deducted directly from your quote, not paid to you as a reimbursement.
Typical Cost After the Grant
| System Type | Typical Installed Cost | BUS Grant | Net Cost to Homeowner |
|---|---|---|---|
| Air Source Heat Pump | £11,000–£16,000 | £7,500 (£9,000 if off-gas-grid oil/LPG) | £2,000–£8,500 |
| Ground Source Heat Pump | £20,000–£35,000 | £7,500 (£9,000 if off-gas-grid oil/LPG) | £11,000–£27,500 |
| Air-to-Air Heat Pump | £3,000–£6,000 | £2,500 | £500–£3,500 |
| Biomass Boiler (rural, off-gas-grid) | £12,000–£19,000 | £5,000 | £7,000–£14,000 |
Current Waiting Times: What's Driving the Backlog
Demand for MCS-certified installers has stayed high through 2026, driven by rising gas prices and local authority retrofit schemes running alongside BUS. Homeowners should expect:
- Initial survey booking: 2–4 weeks from first enquiry with a reputable installer
- Quote-to-installation slot: 6–12 weeks in most regions, longer in high-demand areas like the South East and parts of Scotland's equivalent Home Energy Scotland scheme
- Total time from enquiry to a working heat pump: typically 8–16 weeks end to end
How to Shorten the Wait
- Get 3 MCS installer quotes in parallel rather than sequentially — this is the single biggest lever homeowners have over total wait time.
- Apply in late summer or early autumn to avoid the pre-winter surge in October–December, when installer books fill fastest.
- If you're on oil or LPG, check the enhanced £9,000 window (21 July 2026 – 31 March 2027) before it closes — it's time-limited, unlike the core £7,500 grant which now runs to 2029/30.
- Confirm grant fund availability with your installer upfront — BUS operates on a first-come basis.