Boiler Upgrade Scheme UK: Heat Pump Grants & Solar PV Integration Guide

The transition from fossil-fuel residential heating to electrified low-carbon thermal systems is a central objective of UK climate legislation. Heating and hot water account for the substantial majority of domestic energy consumption in Great Britain. To accelerate the displacement of fossil fuel heating appliances, the UK Government established direct capital funding to lower the barrier of upfront equipment expenditure.

The Boiler Upgrade Scheme (BUS) is a government scheme that provides upfront grants to help reduce the cost of installing heat pumps and biomass boilers in homes and non-domestic buildings.

For property owners pairing modern heat pump technology with rooftop solar photovoltaics, the BUS grant significantly lowers the initial capital expenditure of the thermal system. When combined with solar microgeneration, the electrical energy required to power the heat pump compressor can be partially met by free, clean self-generated power.

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• Air Source Heat Pump Grant: £7,500 towards an air source heat pump (air-to-water).
• Ground Source Heat Pump Grant: £7,500 towards a ground source heat pump (including water source and shared ground loops).
• Biomass Boiler Grant: £5,000 towards a biomass boiler in rural off-gas properties.
• Air-to-Air Heat Pump Grant: £2,500 towards an air-to-air heat pump for residential properties.
• Off-Gas Grid Uplift: Additional £1,500 uplift until March 2027 for properties heated by oil or LPG without mains gas, providing up to £9,000 off cost and installation.
• Delivery Mechanism: Installer-led voucher redemption administered through Ofgem.
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Scheme Overview and Statutory Objectives

The regulatory and policy architecture of the Boiler Upgrade Scheme is divided between ministerial policy oversight and independent statutory administration.

We administer the Boiler Upgrade Scheme on behalf of the Department for Energy Security and Net Zero.

Under this framework, DESNZ establishes overarching policy goals, qualifying eligibility thresholds, and budgetary allocations, while the Office of Gas and Electricity Markets (Ofgem) oversees operational delivery. Ofgem manages installer account verification, reviews and issues digital vouchers, conducts post-installation compliance audits, and disburses payments directly to registered heating contractors.

Geographic Jurisdiction and Devolved Boundaries

Energy efficiency policy across the United Kingdom features devolved administrative frameworks. This scheme is open in England and Wales.

Property owners residing in Scotland or Northern Ireland do not access funding through the Boiler Upgrade Scheme. Instead:

• Scottish homeowners must apply through the Scottish Government's dedicated framework detailed in our Home Energy Scotland grant and loan guide.
• Welsh homeowners can access the Boiler Upgrade Scheme directly, and low-income Welsh households may also qualify for targeted energy improvements through our Wales Warm Homes Nest scheme guide.

Grant Values Across Technology Types

The Boiler Upgrade Scheme provides direct capital discounts across distinct low-carbon thermal equipment categories:

Current grants are available for:

• £7,500 towards an air source heat pump (sometimes called an air-to-water heat pump)
• £7,500 towards a ground source heat pump (including water source heat pumps and those on shared ground loops)
• £5,000 towards a biomass boiler
• £2,500 towards an air-to-air heat pump

Grants are non-repayable capital contributions that do not require monthly repayments or means-tested financial qualification from the property owner.

Off-Gas Grid Uplift: Up to £9,000 Total Grant

To accelerate the replacement of high-carbon liquid fossil fuels in rural regions, the government introduced targeted financial uplifts for rural dwellings.

Until March 2027, you can get an additional £1,500 towards an air source heat pump or ground source heat pump if both:

• your property is heated by oil or LPG
• you do not have a mains gas connection at the property

This provision provides £9,000 off the cost and installation of air-to-water or ground source heat pumps in eligible off-gas grid properties. This is available until 31 March 2027.

Properties situated in rural areas that rely on expensive kerosene heating oil tanks or bulk LPG vessels represent ideal candidates for this uplift. When an off-gas property pairs a £9,000 heat pump grant with domestic solar panels and energy storage, the home can transition from costly fuel deliveries to self-generated electricity and off-peak grid power.

Installer-Led Voucher Mechanics and Application Process

Unlike traditional public grant mechanisms that require homeowners to complete complex administrative paperwork and wait for reimbursement, the Boiler Upgrade Scheme utilizes an installer-led process.

The scheme is installer-led. Installers who are MCS certified can apply for and redeem Boiler Upgrade Scheme vouchers on behalf of property owners.

The process operates through straightforward steps:

1. Quote Acquisition: The property owner engages an MCS certified heat pump installer to assess property heat loss and specify appropriate heating equipment.
2. Online Application: The installer will apply on your behalf on the Ofgem website.
3. Consumer Confirmation: Ofgem contacts the property owner via email to verify that the installer is authorized to act on their behalf and that the property meets basic eligibility criteria.
4. Upfront Grant Deduction: The value of the grant will be taken off the amount you pay for installation. This will be shown on your quotation and invoice.
5. Installation & Redemption: Following installation, the installer submits commissioning documentation and MCS certificates to Ofgem to redeem the voucher value.

Ineligibility Rules and Hybrid Systems Exclusion

The primary goal of the Boiler Upgrade Scheme is the total removal of fossil fuel combustion from residential properties. Consequently, funding is subject to strict eligibility exclusions:

You cannot get a grant for a hybrid heat pump system (for example a combination of gas boiler and air source heat pump).

Systems that retain a gas boiler alongside a small heat pump do not qualify for funding. The installed heat pump must be sized and engineered to satisfy the full space heating and hot water demand of the building. Furthermore, social housing properties and most new-build developments are excluded from the scheme, as new constructions are subject to separate building regulation standards.

For low-income households unable to fund balance-of-system costs, comprehensive whole-house assistance is available under the ECO4 grant scheme.

Thermal Capacity Limits and System Sizing

The Boiler Upgrade Scheme accommodates domestic properties and small commercial facilities while excluding large-scale district heating infrastructure:

The maximum capacity is:

• 45kWth for individual systems
• 70kWth if a heat pump is installed with one or more additional heat pumps
• 300kWth for shared ground loops

The 45kWth capacity ceiling for individual systems provides generous allowance for large domestic properties, detached farmhouses, and historic stone-built dwellings that require substantial thermal output. Shared ground loops supporting multiple domestic dwellings or communal housing blocks can utilize aggregate capacity up to 300kWth.

Economic Synergy: Pairing Heat Pumps with Solar PV

Installing an electrified heat pump alters a property's annual electrical profile, shifting heating expenditures from gas or oil bills directly onto the electricity meter.

Pairing a BUS-funded heat pump with rooftop solar PV and battery storage creates significant operational advantages:

• Spring and Autumn Space Heating: During shoulder months, daytime solar generation provides free electrical energy to run the heat pump compressor during mild weather conditions.
• Domestic Hot Water Production: Throughout summer months, solar electricity powers heat pump hot water cycles, eliminating summer electricity draw.
• Tax Efficiency: In addition to upfront BUS grants, heat pumps and solar arrays benefit from UK VAT relief on solar panels and batteries, ensuring zero VAT on installation services until 31 March 2027.

For homeowners in England and Wales replacing aging gas, oil, or LPG boilers, the Boiler Upgrade Scheme delivers substantial capital support of £7,500 to £9,000, establishing an economical foundation for a fully electrified, solar-powered home.