Author: By Sailax Editorial Team | Last Updated: April 2026
Published on: April 10 2026
The Boiler Upgrade Scheme (BUS) is a government scheme for eligible properties in England and Wales that provides grants towards qualifying low-carbon heating installations.
As of August 2026, the standard grant is £7,500 for eligible air-to-water heat pumps and ground source heat pumps. An enhanced £9,000 grant is available for certain eligible off-gas-grid properties from 21 July 2026 until 31 March 2027, subject to the specific conditions of the scheme. Current grant values and eligibility should always be checked against the latest GOV.UK and Ofgem guidance before an installation is agreed.
Eligible property owners may receive a Boiler Upgrade Scheme grant towards a qualifying installation, subject to the scheme’s eligibility requirements.
Sailax can support homeowners through the assessment, system design and installation process. However, eligibility and approval are determined under the Boiler Upgrade Scheme rules and cannot be guaranteed by an installer.
The grant can reduce the upfront cost of an eligible installation, while the suitability and performance of the heating system depend on the property, system design, installation and operating conditions.
The Boiler Upgrade Scheme (BUS) is a UK government incentive available in England and Wales that helps reduce the upfront cost of eligible low-carbon heating installations. The scheme provides grants towards qualifying heat pumps and biomass boilers, subject to specific eligibility and technical requirements.
Understanding how the scheme works, eligibility requirements, and the application process is important before committing to an installation. This guide explains the current BUS rules in practical terms for homeowners and other eligible property owners.
Current-rule note: Grant values and scheme requirements can change. This article has been checked against GOV.UK and Ofgem information available in August 2026. Eligibility and approval are subject to the scheme rules in force when the application is properly made.
The Boiler Upgrade Scheme is an England and Wales government scheme designed to support the installation of eligible low-carbon heating systems. Depending on the technology and property circumstances, the scheme can provide a grant towards air-to-water heat pumps, air-to-air heat pumps, ground source heat pumps and eligible biomass boilers.
The scheme is installer-led. An MCS-certified installer applies for and redeems the BUS voucher on behalf of the property owner, while Ofgem administers the scheme. The grant is intended to reduce the upfront cost of the qualifying installation rather than guarantee a particular long-term energy saving.
The Boiler Upgrade Scheme remains open in 2026, and the government increased the scheme budget in April 2026. Updated grant categories and values also took effect during 2026.
As of August 2026:
The £9,000 off-gas-grid uplift is not automatically available to every property without a mains gas connection. Specific replacement-heating and property conditions apply, so the current Ofgem guidance should be checked before publishing or quoting the grant value to a customer.
Eligibility depends on the property, existing heating system, proposed technology, installer and other scheme requirements.
The scheme is available in England and Wales. For retrofit installations, the BUS-funded system must replace an existing qualifying fossil-fuel or electric heating system, subject to the detailed rules. New-build properties are generally excluded, although certain eligible self-build properties can qualify.
Working with an MCS-certified installer can help establish whether a proposed installation meets the relevant technical and administrative requirements, but an installer cannot guarantee grant approval.
The exact requirements depend on the installation and the current version of the BUS regulations and guidance. Key requirements include:
An EPC is important, but the rules are more specific than simply requiring an EPC rating of C or above. Where a property has a valid EPC, the certificate number is normally provided as part of the process, and specific insulation recommendations can affect eligibility.
A BUS application can be delayed, rejected or require additional information if the property, installer, technology or documentation does not satisfy the scheme rules.
Understanding these requirements before installation can reduce avoidable administration issues.
Potential issues include:
A compliant installer can help identify issues before an application is submitted, but no installer can guarantee that Ofgem will approve a particular application.
The main financial benefit of BUS is the upfront grant contribution towards a qualifying installation.
The amount a homeowner actually pays depends on the total quotation, system specification, property requirements, installation complexity and the grant applicable to that property. BUS should therefore not be presented as a guarantee of a particular final installation price or long-term saving.
| System Type | Current Standard Grant | Potential Enhanced Grant | Notes |
|---|---|---|---|
| Air-to-Water Heat Pump | £7,500 | £9,000 for certain eligible off-gas-grid properties | Subject to current BUS rules |
| Ground Source Heat Pump | £7,500 | £9,000 for certain eligible off-gas-grid properties | Subject to current BUS rules |
| Air-to-Air Heat Pump | £2,500 | See current scheme rules | Residential eligibility applies |
| Biomass Boiler | £5,000 | Different rules may apply to eligible off-gas-grid cases | Subject to current BUS rules |
The standard £7,500 values and the £9,000 off-gas-grid uplift have been confirmed in the current GOV.UK and Ofgem guidance available in July/August 2026. The £9,000 uplift applies from 21 July 2026 to 31 March 2027 for qualifying off-gas-grid installations and is subject to specific conditions.
The BUS grant can reduce the initial cost of an eligible installation. Any additional running-cost saving depends on the individual property and system.
Factors that affect ongoing costs include:
For this reason, homeowners should request a property-specific assessment rather than rely on a fixed savings percentage.
The grant itself is subject to eligibility and approval and should not be described as guaranteed funding before the relevant application has been properly made and approved.
The BUS application process is installer-led. An eligible property owner normally works with an MCS-certified installer, who assesses the proposed installation and submits the BUS voucher application on the owner's behalf.
Eligible property owners may receive a Boiler Upgrade Scheme grant towards a qualifying installation, subject to the scheme's eligibility requirements.
The process generally involves:
The full process can vary by property, installer availability, application requirements and Ofgem processing. It should not be advertised as having a guaranteed approval time.
Don't rely on assumptions about eligibility.
Eligibility and approval remain subject to the Boiler Upgrade Scheme rules and Ofgem's assessment.
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There is no single guaranteed timeframe for every BUS installation. The timing depends on property assessment, documentation, installer availability, application processing and installation scheduling.
Once a BUS application has been approved, the current Ofgem property-owner guidance states that the installer generally has three months from approval to complete the installation, with six months applying to ground source heat pump installations. If the required work is not completed within the applicable period, a new application may be required.
The exact sequence can vary, but homeowners can generally expect:
Homeowners should confirm the expected schedule with their installer rather than relying on a fixed four-to-eight-week promise.
BUS provides an upfront grant towards eligible low-carbon heating installations. It does not automatically cover every cost associated with improving a property.
The current scheme includes eligible:
Depending on the property and project, homeowners may still need to budget separately for:
A BUS grant cannot be assumed to cover every additional improvement. The installer should provide a clear quotation showing what is included in the project price and how the grant is applied.
The Boiler Upgrade Scheme is available in England and Wales. It does not apply to Scotland or Northern Ireland, which have separate policies and support programmes.
Homeowners in Scotland should check the current support available through the relevant Scottish programmes. Northern Ireland also has its own energy-efficiency and heating support arrangements.
Choosing the right heating system depends on the property's construction, heat loss, existing heating system, available space, hot water requirements and budget.
A professional assessment can help determine whether an air-to-water, ground source or another eligible system is appropriate.
Several factors influence the choice of heating system:
The objective should be an appropriately designed system rather than simply selecting the largest or cheapest available heat pump.
In some circumstances, the Boiler Upgrade Scheme can be combined with other support for separate energy-efficiency improvements, such as insulation, provided the funding rules allow it. You cannot use another public grant to cover the same purchase or installation costs as the BUS-funded system. Eligibility and approval are subject to the scheme rules.
Your EPC can affect eligibility. Current BUS requirements include rules relating to EPC evidence and certain insulation recommendations. Where applicable, loft or cavity-wall insulation recommendations may need to be addressed unless an exemption applies. The exact requirements should be checked against the current Ofgem guidance for the application.
Not automatically. Radiator upgrades are primarily a system-design issue. A heat-loss calculation and emitter assessment can determine whether existing radiators can deliver the required heat at the intended heat pump flow temperature.
Heat pump sizing should be based on the property's heat demand and system design. Factors can include heat loss, building construction, insulation, floor area, windows, design outdoor temperature and required indoor temperatures.
The installer is responsible for ensuring the proposed system meets the relevant technical and BUS requirements. Grant eligibility and approval remain subject to the scheme rules.
If an application cannot be approved, the installer should identify the reason and explain whether the issue can be corrected. Depending on the circumstances and current rules, a new or amended application may be possible. There is no guarantee that a future application will be approved.
A properly designed heat pump can use less electricity than a direct electric heating system for the same amount of delivered heat because it transfers ambient heat into the property. Compared with gas heating, the financial result depends on the heat pump's seasonal performance, gas and electricity tariffs, property heat loss and operating conditions.
Homeowners should use property-specific calculations rather than assume a fixed saving percentage.
Not necessarily. Many air source heat pump installations can be carried out under permitted development rights when the applicable conditions are met. However, listed buildings, conservation areas, flats, multiple heat pump installations and other circumstances can change the planning position.
The installer should check the specific property and local requirements before installation.
No. The BUS does not provide a grant for replacing an existing low-carbon heating system such as a heat pump. The scheme is intended for qualifying installations that meet the current replacement and eligibility requirements.
Installation quality and system design can significantly affect heat pump performance. Correct sizing, heat-loss calculations, radiator or emitter selection, controls, hydraulic design, commissioning and user settings all influence operating efficiency.
A high-quality installation can support good performance, but actual running costs and savings vary by property and usage.
The BUS can apply to eligible property owners and qualifying properties, subject to the scheme rules. Landlords should confirm the specific property and proposed installation meet the current requirements before committing to the project.
The grant should not be presented as guaranteed until the relevant eligibility and application requirements have been satisfied.
The Boiler Upgrade Scheme can substantially reduce the upfront cost of an eligible low-carbon heating installation in England and Wales.
As of August 2026, the standard BUS grant is £7,500 for eligible air-to-water and ground source heat pumps. Certain eligible off-gas-grid properties can receive an enhanced £9,000 grant from 21 July 2026 until 31 March 2027, subject to the specific conditions of the scheme.
Eligible property owners may receive a Boiler Upgrade Scheme grant towards a qualifying installation, subject to the scheme’s eligibility requirements.
For homeowners considering a heat pump, the most important steps are to confirm eligibility, assess the property properly, select an appropriately designed system, understand the full installation quotation, and use an appropriately certified installer.
Sailax can support the assessment, system design and installation process, but grant eligibility and approval remain subject to the current Boiler Upgrade Scheme regulations and Ofgem requirements.
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