BOILERS GUIDE
Biomass Boiler Grants UK 2026: BUS Eligibility, Costs and Fuel
The Boiler Upgrade Scheme pays £5,000 toward a biomass boiler in England and Wales, running until 2030 under the Warm Homes Plan.
Check eligibilityLast updated May 2026
The Boiler Upgrade Scheme pays £5,000 toward a biomass boiler in England and Wales, running until 2030 under the Warm Homes Plan.
Answer a few quick questions to see which government energy grants you're eligible for. Free, instant results.
Eligibility at a glance
Free eligibility check
The biomass boiler grant is £5,000 under the Boiler Upgrade Scheme, the government’s low-carbon heating subsidy running until 2030 under the Warm Homes Plan.
Biomass sits alongside air source heat pumps (£7,500) and ground source heat pumps (£7,500) as the three technologies BUS funds. Your installer applies on your behalf and the grant comes off your invoice directly. You never handle the paperwork or wait for a refund. The full policy framework is set out on GOV.UK’s Boiler Upgrade Scheme page.
Biomass is the smallest slice of BUS uptake by a long way. Most grants go to air source heat pumps because they suit a wider range of properties. Biomass tends to win in one specific situation: rural, off-gas homes with space for a pellet store and an owner who wants the warmth and feel of a traditional boiler rather than the lower flow temperatures of a heat pump.
You qualify if your property is off the gas grid, in England or Wales, and meets the EPC and certification rules.
Off the mains gas grid
This is the rule that catches most applicants out. Biomass funding is restricted to properties not connected to the gas network. If you currently burn oil, LPG, electricity or solid fuel, you’re in. If you have a gas meter, you’re not.
Valid EPC with no outstanding insulation recommendations
The EPC must be under 10 years old. If it lists loft or cavity wall insulation as a recommended measure, you’ll need to install those first (or get an exemption). Check your current EPC on the official register.
MCS-certified boiler and installer
Both the appliance and the installer must hold MCS certification. Your installer registers the grant claim through MCS, not you.
England or Wales only
BUS doesn’t cover Scotland or Northern Ireland. Scottish homeowners apply through Home Energy Scotland, which offers a £7,500 grant plus an interest-free loan.
Property type
Domestic properties and small non-domestic premises qualify. Self-build homes are eligible from the 2024 amendment onwards. New-build properties built by developers are excluded.
The eligibility checker runs your details against BUS, ECO4 and the local Warm Homes grants in 2 minutes — then tells you which technology actually fits your property.
The off-gas rule is the gatekeeper. If you’re on mains gas, you cannot use BUS for biomass, full stop. The policy reasoning is that biomass replaces high-carbon fuels (oil, LPG, coal) more cleanly than it replaces gas, so government funding is targeted accordingly.
If the EPC flags missing insulation, you have two routes: install it first (often funded separately through ECO4 if you qualify), or apply for an insulation exemption with evidence that the work isn’t feasible.
Installed cost runs £10,000-£19,000 before the grant, leaving £5,000-£14,000 to pay.
The range is wide because biomass systems vary more than gas boilers. A modest 15kW pellet boiler in a small rural cottage with simple pipework is at the bottom end. A 30kW log gasification boiler with a thermal store, pellet hopper, and full system upgrade in a five-bedroom farmhouse is at the top.
| System type | Typical installed cost | After £5,000 BUS grant |
|---|---|---|
| Pellet boiler, 15-20kW | £10,000-£14,000 | £5,000-£9,000 |
| Pellet boiler, 25-35kW | £14,000-£19,000 | £9,000-£14,000 |
| Log gasification boiler | £12,000-£17,000 | £7,000-£12,000 |
| Wood chip (rural/large) | £18,000-£25,000 | £13,000-£20,000 |
Key cost drivers: the pellet store (£1,500-£4,000 depending on size and whether it’s an indoor hopper or external silo), the thermal buffer tank (£800-£2,000), pipework changes (£500-£2,500), and the flue (£600-£1,500 for a twin-wall stainless system through a roof).
According to Energy Saving Trust analysis, biomass running costs sit roughly between oil and air source heat pump territory, depending on pellet prices and whether you have somewhere to store fuel in bulk.
Usually yes, especially against LPG. Against oil, it’s closer.
Wood pellets cost around 7-9p per kWh delivered in bulk at 2026 prices, compared with roughly 8-10p per kWh for heating oil and 11-14p for LPG. The catch is the bulk delivery. If you’re buying pellets in 10kg bags from a builder’s merchant, you’ll pay 50-70% more per kWh than bulk delivery, which wipes out the running-cost advantage.
Biomass economics only work if you have space for a 3-tonne pellet silo and a clear delivery route for a blown-delivery tanker. Without that, you’re paying bag prices, and at bag prices oil is cheaper.
A typical four-bedroom off-gas home uses 4-6 tonnes of pellets per year. At bulk prices that’s £1,400-£2,200 in fuel. At bag prices it’s £2,400-£3,800. The fuel bill maths is the single most important calculation before signing up.
Your situation
Off-gas, rural property with space for a pellet silo
Best route
You don’t. Your MCS-certified installer applies on your behalf through the Ofgem portal.
Use the MCS Installer Database to find accredited engineers in your area. Get 2-3 quotes; biomass installation is specialist work and prices vary significantly.
The installer surveys the property, confirms space for the boiler and fuel store, and checks your EPC for any outstanding insulation recommendations.
Once you’ve agreed the quote, the installer submits the BUS application to Ofgem. The voucher is approved within around 14 days.
Approval rates are high for biomass applications because the eligibility rules are mechanical. If your property is off-gas, your EPC is clean, and the installer is MCS-accredited, the application goes through. The bottlenecks are usually finding an installer with capacity (biomass installer numbers are thinner than gas or heat pump engineers) and lining up a bulk pellet supplier in your area.
Common mistakes that delay or block biomass applications
Biomass has more failure points than a standard boiler swap. Watch for the following before you commit:
The pellet supply issue is the one most people underestimate. The MCS Installer Database lists installers but doesn’t list fuel suppliers. Get supplier quotes for bulk delivery to your postcode before committing to biomass over a heat pump.
Air source heat pumps are the obvious alternative for off-gas properties, and they get a bigger grant.
Best for
Off-gas homes with reasonable insulation; properties without space for a pellet store
What it pays
£7,500 toward installation
Main catch
Lower flow temperatures may need larger radiators; works best in well-insulated homes
Runs until
2030 under the Warm Homes Plan
Best for
Rural properties with land for a ground loop or borehole
What it pays
£7,500 toward installation
Main catch
Total install cost £18,000-£35,000; ground works are disruptive
Runs until
2030 under the Warm Homes Plan
If you’re on qualifying benefits and currently use oil or LPG, ECO4 can also fund a heating upgrade, though biomass isn’t one of the technologies it typically covers. The Warm Homes: Local Grant administered by councils sometimes funds biomass for fuel-poor rural households where heat pumps aren’t viable.
For on-gas homes considering low-carbon heating, biomass isn’t an option under BUS. The realistic alternatives are an air source heat pump (with the £7,500 grant) or a high-efficiency condensing gas boiler paid for privately. Our new boiler cost guide covers the gas option in detail.
Boiler Upgrade Scheme 2026
The full BUS guide — heat pumps, biomass, eligibility and how the £7,500 grant works.
Read guideBoiler Grants UK 2026
Every scheme that funds a new boiler — ECO4, BUS, Warm Homes Local and the non-benefits route.
Read guideHeat Pump vs Biomass: Which Suits Your Home?
Side-by-side comparison of running costs, install complexity and grant value.
Read guideNew Boiler Cost UK 2026
What you’ll pay for a gas boiler if biomass and heat pumps don’t fit.
Read guideCommon questions
Your situation
Off-gas property but limited outdoor space
Best route
Air source heat pump under BUS (£7,500)Your situation
On the mains gas grid
Best route
Not eligible for biomass BUS — consider ASHP or efficient gas boilerYour situation
Scottish property
Best route
Home Energy Scotland grant plus loanYour situation
On qualifying benefits with EPC D-G
Best route
ECO4 (gas boiler replacement)Old boiler removed, new biomass system fitted, pellet store installed, commissioning completed. Allow 3-5 days on site for most installations.
The £5,000 is deducted from your final bill. The installer claims it back from Ofgem. You never see paperwork beyond signing off the work.