The Boiler Upgrade Scheme (BUS) is a government capital grant that reduces the upfront cost of certain low-carbon heating installations, and biomass boilers are one of the technologies it can cover, though not in every case. Whether a given installation qualifies depends on the property, the fuel source already in use, and the boiler specification.

Which properties can apply

The scheme is aimed at homes that cannot reasonably use mains gas, so eligibility generally turns on whether the property is off the gas grid. A house currently heated by oil, LPG, direct electric, or coal is the typical candidate; a property already on mains gas is unlikely to qualify for a biomass boiler grant even where a biomass boiler would otherwise be a sensible fit. This condition sits ahead of everything else the scheme asks, because it determines whether an application is worth making at all.

What the boiler itself has to satisfy

A qualifying biomass boiler needs to meet the scheme's own technical and emissions standards, and it needs to be installed by an installer certified under MCS (the Microgeneration Certification Scheme), the accreditation body for installers of low-carbon heating systems. A pellet stove used for space heating in one room is a different category of appliance, and the scheme's biomass provision is built around the boiler. If you are weighing a boiler against a stove for your own heat demand, read how pellet stoves and boilers actually work before assuming either qualifies.

What the grant pays for, and what it does not

The grant contributes to the installed cost of the boiler and its associated heating system components. It does not cover the fuel store, the season's pellet supply, or ongoing servicing, and it does not remove the need for the property to have adequate insulation and a suitable heat distribution system for the appliance to perform as specified. A biomass boiler grant is not a verdict on whether biomass is the right technology for your house; that is a separate question about heat demand, storage space, and how the property compares against a heat pump. Biomass against a heat pump: an honest comparison covers that decision directly, and the suitability assessment works through the property conditions that matter before cost enters the picture.

Why this needs checking, not assuming

Scheme rules, grant amounts and qualifying criteria are set and revised by the scheme administrator, and they have changed before. An installer telling you a system "qualifies for the grant" is stating an opinion about the scheme; the only reliable answer comes from checking your specific property and boiler specification against the scheme's own current rules at the point you apply.

The Boiler Upgrade Scheme (BUS) is run by Ofgem on behalf of the government, and Ofgem's own published guidance is the version that actually decides whether a particular installation qualifies. Installer brochures, sales calls and even well-meaning forum threads summarise the rules, but summaries drift out of date as the scheme is amended, and a summary is not the thing an assessor checks your application against.

Where the rules actually live

Search for the Boiler Upgrade Scheme on the Ofgem website. The eligibility conditions, excluded property types and current grant structure are set out there, and that page is updated when the scheme changes, which a printed brochure or a third-party summary is not.

What to have ready before you ask

Before contacting an installer or checking eligibility, it helps to have the basics to hand:

• Your property address and confirmation of whether it is connected to the gas grid
• Details of your current heating system, including the boiler it would replace
• An Energy Performance Certificate (EPC) for the property, if one exists
• A quote from an installer certified under MCS (the Microgeneration Certification Scheme, which certifies both the installer and the specific biomass boiler model for low-carbon heating grants)

Both parts of that last point matter separately: the installer needs current MCS registration, and the boiler itself needs to be an MCS-certified product. A quote that skips over either is not a scheme-compliant quote, whatever else it promises.

Why an installer saying you'll qualify is not the same as qualifying

An installer can tell you a property looks eligible based on their experience, but they do not decide the outcome. The application is assessed against Ofgem's current rules, and only Ofgem's decision is the one that counts. Installer certification can be checked directly. The MCS register lets you confirm whether a named installer and a named product are currently certified.

Grant terms and amounts change, and this page cannot state a figure as settled without risking being wrong by the time you read it. Read Grants and Schemes for Biomass Heating for how the Boiler Upgrade Scheme sits alongside other support, and check the MCS register and Ofgem's own BUS guidance before treating any installer's eligibility claim as final. If you are still weighing biomass against the alternatives, the suitability assessment is a reasonable next step.