How to Apply for the Boiler Upgrade Scheme – A Complete UK Guide

The Boiler Upgrade Scheme (BUS) is a government grant programme that provides a one-off payment to homeowners in England and Wales towards the upfront cost of installing a low-carbon heating system. The scheme replaced the Renewable Heat Incentive in April 2022 and was extended and expanded in subsequent years, with grant amounts increasing to £7,500 for heat pumps in 2023. The purpose is to make the higher upfront cost of heat pump installation more comparable to a standard gas boiler replacement, accelerating uptake of low-carbon heating in existing housing stock.

The key practical point for homeowners to understand is that you do not apply for the grant yourself. The Boiler Upgrade Scheme is applied for by your installer on your behalf at the point of installation. This means the grant is deducted from the cost of the installation before you pay – you do not pay the full amount and wait for a rebate. Your job as a homeowner is to establish eligibility, find an MCS certified installer, and ensure your property meets the basic requirements before work begins.

What Is the Boiler Upgrade Scheme?

The Boiler Upgrade Scheme provides grants of up to £7,500 for air source heat pumps and ground source heat pumps, and £5,000 for biomass boilers in rural areas. The scheme is administered by Ofgem on behalf of the government, and funding is allocated on a first-come, first-served basis each year. The scheme is designed specifically for owner-occupied properties in England and Wales – Scotland has its own separate scheme (Home Energy Scotland) and different grant structures apply there.

Eligibility – Who Qualifies?

The scheme is open to owner-occupiers and landlords of properties in England and Wales. The property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft insulation or cavity wall insulation – if the property has these recommendations on its EPC, they must be completed before a BUS application can proceed. This requirement was introduced to ensure that heat pumps are being installed into homes with adequate insulation, which is necessary for the heat pump to operate efficiently.

Properties must not have previously received a grant under the Boiler Upgrade Scheme or its predecessor, the Renewable Heat Incentive. There is no income threshold – the scheme is not means-tested and is available to all eligible property types regardless of household income. New build properties are excluded, as are social housing properties (which have separate funding routes). Properties that already have a heat pump installed are not eligible for a second grant.

It is also worth understanding what the EPC rating requirement does not mean. The scheme does not require a property to achieve a specific EPC band – a property with an E or F rating is not automatically excluded. What matters is solely whether the EPC lists loft or cavity wall insulation as a recommendation. If those two specific measures are not listed, or have already been completed and reflected in an updated EPC, the property can proceed. A property with solid walls that cannot have cavity wall insulation installed is not blocked from applying – the recommendation only applies where cavity wall insulation is technically possible. If you are unsure how to read your EPC, the EPC register on gov.uk shows the full recommendations list for your property.

How the Application Process Works

The Boiler Upgrade Scheme application is handled entirely by your MCS certified installer, not by you directly. Your role as a homeowner is to confirm eligibility, agree the installation contract, and sign a declaration confirming the information provided is accurate. The installer submits the application to Ofgem through the BUS voucher system, and if approved, receives a voucher that is redeemed against the cost of installation. The grant is deducted from your invoice – you pay the balance only.

Vouchers issued under the scheme are valid for three months from the date of issue. If installation cannot be completed within this window, the installer can apply for an extension. The full installation and commissioning of the system must be completed before the voucher can be redeemed. Ofgem carries out post-installation checks on a proportion of installations to verify that work has been carried out to the required standard by a qualified MCS installer.

Finding an MCS Certified Installer

Only MCS (Microgeneration Certification Scheme) certified installers can submit Boiler Upgrade Scheme applications. This is a non-negotiable requirement – no amount of prior correspondence with a non-MCS installer or self-arranged equipment purchase will allow a grant application to proceed. The MCS certification ensures that installers have the training, equipment and processes to install heat pumps to the required standard, and provides a framework for redress if work is not completed satisfactorily.

Finding an MCS certified installer is straightforward using the MCS installer search at mcscertified.com, which allows you to search by postcode and technology type. You should obtain at least three quotes before proceeding, as prices for heat pump installation vary considerably by installer and by the specifics of the property. The cost of an air source heat pump installation in the UK typically ranges from £10,000 to £18,000 before the grant, depending on property size, existing heating system, and whether the heat distribution system (radiators or underfloor heating) needs upgrading.

Common Questions About the Scheme

The most frequently asked question about the Boiler Upgrade Scheme is whether a property needs to be fully insulated before applying. The answer is that only specific EPC recommendations for loft insulation and cavity wall insulation block an application – the EPC does not need to show an A or B rating, and other insulation recommendations on the EPC (such as solid wall insulation or floor insulation) do not prevent an application proceeding.