What is the Boiler Upgrade Scheme?

To help homeowners understand this scheme, we have put together a series of Q&As relating to the Boiler Upgrade Scheme here.

Quick links for this blog…

In this blog, we will explain:

• Why has the Boiler Upgrade Scheme been introduced?
• What funding is available through the Boiler Upgrade Scheme?
• Who is eligible for the Boiler Upgrade Scheme?
• Why should I switch to a renewable energy heating system?
• How do you apply for the Boiler Upgrade Scheme?
• What are the key BUS requirements?

Why has the Boiler Upgrade Scheme been introduced?

When the Government announced its Heat and Buildings Strategy in the Autumn of 2021, emphasis was placed on air source heat pumps as a low carbon heating solution which could significantly help reduce the carbon footprint of household heating. A lot of homes today are currently kept warm by a traditional fossil fuel boiler, such as a gas or oil boiler, but as the country moves towards achieving Net Zero, many homes will need to turn to renewable energy to reduce their dependency on high carbon fuels. This is where air source heat pumps, such as the Aerona³ heat pump and Aerona 290 heat pump from Grant, can step in.

Air source heat pumps, which utilise the heat energy in the air and transfer it into useable energy within a heating system, are already helping thousands of UK homes with their heating and hot water. Installing an air source heat pump is not the same as installing a boiler so the installation costs can be higher. This is one of the reasons why the Government introduced the Boiler Upgrade Scheme (BUS) to provide consumers with financial support to assist their transition to low carbon heating. 

In Spring 2022, after the Domestic RHI closed, the Government launched its Boiler Upgrade Scheme (BUS) funding programme to help homeowners make the switch from a fossil fuel boiler to a renewable heating source, such as an air source heat pump.

What funding is available through the Boiler Upgrade Scheme?

Through the Boiler Upgrade Scheme (BUS), eligible applicants in England and Wales can receive a capital grant to support the installation of a low carbon heating system. Grants of £7,500 are available towards the installation and capital costs of air source heat pumps and ground source heat pumps. Funding is also available for air-to-air heat pumps and, in limited circumstances, for biomass boilers. 

Through BUS, significant levels funding are being made available until 2028.

What BUS funding is available for rural homes with oil-fired boilers or LPG?

On 21st April 2026, the Government announced a temporary uplift in BUS funding which will be available to homes which are reliant on heating oil or LPG. When this uplift becomes available, eligible homeowners with an oil boiler or LPG boiler will be able to claim £9,000 towards the installation of an air source heat pump.

At the time of writing, it has not yet been confirmed when this additional funding will become available, although it is anticipated to be sometime in July 2026 and remain available until the end of March 2027.

Homeowners with an existing live BUS voucher may be able to revoke their voucher and reapply at the higher grant level once it is available, subject to Ofgem rules at that time. Please note, applications are only eligible where the low carbon heating system has been commissioned no more than 120 days prior to an application being made.

Details of the uplift, including eligibility and timing, are subject to change.

What BUS funding is available for homes with gas boilers?

Homes using a gas boiler can claim £7,500 through the Boiler Upgrade Scheme to install an air source heat pump. Please note, the temporary uplift announced by the Government in April 2026 will not be available to homeowners with gas central heating systems because the £9,000 BUS grant will be temporarily available to eligible homes reliant on heating oil or LPG only.

Who is eligible for the Boiler Upgrade Scheme?

The BUS is open to applicants in England and Wales. The grants are available to domestic and non-domestic buildings, supporting systems up to a capacity of 45kWth. Social housing and new builds are not eligible however, domestic, custom new/self-builds can apply.

Air source heat pumps and ground source heat pumps are eligible provided they are being installed to replace an existing fossil fuel system or direct electric heating system. The only exception to this is with custom new builds whereby a heat pump installation would be eligible for a grant.

In limited circumstances, biomass boilers can be eligible for a grant in rural areas when they are replacing an existing fossil fuel system which is not fueled by mains gas or direct electric systems.

Please be advised the fossil fuel hybrid systems or systems used for process heating are not eligible.

Why should I switch to a renewable energy heating system?

Besides the financial incentive offered through the Boiler Upgrade Scheme, switching to a more sustainable heating solution, such as an air source heat pump, has a whole range of benefits. One benefit is the more positive impact that a renewable heat source has on the environment. Air source heat pumps are low carbon sources of heat, utilising the heat energy in the air and using this to heat your home and running on electricity, rather than fossil fuels.

Another benefit is efficiency. When designed and installer properly, heat pumps can heat your home incredibly efficiently - for example, the Aerona 290 6.5kW heat pump has an exceptional SCOP of 5.08 (35°C water) which means that for every kilowatt of energy used to run the heat pump, over 5kW of energy is being given to the heating system in return. 

Furthermore, air source heat pumps are very low maintenance and, if looked after properly, will last for many years of reliable operation.

How do you apply for the Boiler Upgrade Scheme?

Ofgem are administering the Scheme and vouchers are provided as part of the grant application and redemption process, a process which is led by the installer.

The installer will need to submit two applications – a BUS voucher application and a redemption application. Provided the BUS voucher application meets the eligibility criteria and consent from the property owner is received, Ofgem will then issue a BUS voucher. This BUS voucher can then be redeemed once the new heating system has been installed and commissioned. The grant will be paid to the installer, thus reducing the invoicing cost for the homeowner.

What are the key BUS requirements?

It is important that both the installing engineer and homeowner are aware of the full list of eligibility requirements for the Scheme. The heat pump unit that is selected will need to meet certain performance and efficiency thresholds, for example the heat pump installed must have a minimum SCOP of 2.8. The installer who completes the installation will also need to meet certain requirements. Alongside being a competent heat pump engineer, all installers participating in the Scheme will need to be MCS certified and members of a Consumer Code that will ensure that customers are protected by a Trading Standards Institute Approved Code of Practice.

What are the key dates?

The BUS opened to eligible installations commissioned and MCS certified after 1st April 2022. In September 2023, the Department for Energy Security and Net Zero issued a change notice to increase the BUS grant level for air source heat pumps and ground source heat pumps. Since 23rd October 2023, installers have been able to apply for the newly increased grant amounts. In June 2025, the Government confirmed that funding to the Boiler Upgrade Scheme will increase each year to 2029/30 as part of its Warm Homes Plan.

In April 2026, a temporary uplift in funding was announced by Government for homes heating by oil or LPG – the dates when this additional funding will be available are yet to be finalised.

For the latest information and further details about the procedures to apply for the Boiler Upgrade Scheme, please refer to www.ofgem.gov.uk/environmental-and-social-schemes/boiler-upgrade-scheme-bus. The Department for Business, Energy and Industrial Strategy have also published a useful guide about the Boiler Upgrade Scheme which you can download here. 

To learn more about air source heat pumps, and other sustainable heating solutions, contact the team at Grant today.

The answers given in this blog are correct at the time of publication.

[This blog was originally published on 14th January 2022 and is regularly reviewed & updated with BUS updates. The content was most recently updated on 7th May 2026]

Important: BUS applications submitted on or after 23rd October 2023 are eligible to claim £7,500 towards their new air source heat pump, an increase from £5,000 which was previously available through BUS.