Boiler Upgrade Scheme (BUS)

This page summarises key information about the Boiler Upgrade Scheme (BUS) for installers.

For full scheme details, we encourage you to read the Boiler Upgrade Scheme guidance for installers.

Some of the key eligibility criteria for the scheme are set out below. For a full explanation of all eligibility criteria, see chapter 3 of the Boiler Upgrade Scheme guidance for installers.

Installer eligibility and responsibilities

As an installer, you are responsible for applying for the Boiler Upgrade Scheme grant on behalf of the property owner. To apply, your business must be certified to install the relevant technology under the Microgeneration Certification Scheme (MCS). 

Once you’re ready to get started, it’s your responsibility to be familiar with the BUS Regulations 2022 (as amended) which define the scheme’s eligibility requirements. 

The BUS Guidance for Installers explains all scheme requirements in more detail. Below we have outlined several of the key eligibility requirements, as well as how to create an account to apply.  

Property eligibility

In order to be eligible for a BUS-funded installation, a property must be in England and Wales. 

Properties which are not eligible include: 

• social housing
• new builds (except where they are ‘eligible self-builds’, see below) that have been built mainly using the labour or resources of the first owner, have never been owned by a business or organisation and are not part of an excluded property development
• commercial a non-residential building (where installing an air-to-air heat pump) 

Requirements for retrofits 

Requirements that apply for installations in retrofit properties include: 

• the Boiler Upgrade Scheme-funded installation must replace an existing fossil-fuel or electric heating system
• if the property has a valid Energy Performance Certificate (EPC), the certificate number must be provided
• if a property does not have a valid EPC, installers will need to provide alternative evidence to demonstrate eligibility

Requirements for eligible self-builds 

Self-build properties are considered eligible for the Boiler Upgrade Scheme if all the following apply: 

• the property has been built mainly using the labour or resources of the first owner,
• the property has never been owned by a business or organisation, and
• the property is not part of an excluded property development 

Requirements for the uplifted grant value for off-gas grid properties 

To be eligible for the £9,000 uplifted grant value, properties must be off the gas grid and installing either an air-to-water or a ground source heat pump only. To qualify as an off-gas grid property under BUS, a property must not: 

• be fuelled by mains gas (capped or clamped supply meter points are still considered as being fuelled by mains gas) 
• have a record of an existing gas meter point  
• be attached to a heat network 
• be a new-build property 

As well as the property being off the gas grid, the heating system being replaced must be fuelled by either: 

• oil
• liquefied petroleum gas (LPG)

Technologies eligible for installation

The following technologies are eligible for the BUS: 

• air-to-water heat pumps
• air-to-air heat pumps
• ground source heat pumps
• ground source heat pumps as part of a shared ground loop
• biomass boilers 

Other eligibility criteria  

Installers must pass on the full value of the BUS grant as an upfront discount to the property owner. This discount must appear at the quote stage prior to the installation, and on the invoice following the installation.  

Installers must not request or accept payment of this value. Failure to meet these requirements may lead to the rejection of a voucher application or revocation of a voucher. 

Eligible technology requirements 

Installers must ensure that the new heat pump or biomass boiler complies with requirements of the BUS regulations. These include: 

• the new heat pump or biomass boiler must be commissioned no more than 120 days prior to the voucher application being properly made
• the new heat pump or biomass boiler must meet the standards approved and published by the Secretary of State. To help you check, you can use the Boiler Upgrade Scheme Product Eligibility List, which is a subset of the MCS product eligibility list
• the new heat pump must be sized to meet the full space heating needs of the property, whether or not it is installed alone or in combination with a supplementary appliance
• the new heat pump must be capable of meeting the full space heating and hot water heating needs of the property, either alone or in combination with a supplementary appliance
• any supplementary heating system must not be fuelled by fossil fuels
• the new heating system must only provide heating to the property being applied for. Including any ‘related properties’ that the owner or occupier can use such as an annex or swimming pool
• the new heating system must have a maximum capacity of 45kWth or 70kWth when installed as a cascade system
• for shared ground loops, the combined capacity of all heat pumps on the shared loop cannot exceed 300kWth
• the new heat pump must not have been used prior to commissioning, except in limited circumstances, e.g. to dry out plasterwork during construction or renovation. For shared ground loops, a new heat pump can connect to an existing shared loop
• the new heating system must not be a hybrid system that combines a heat pump with fossil fuel heating
• the new heating system must replace either a fossil fuel heating system or an electric heating system
• the property owner has not received another grant from public funds to cover any of the purchase or installation costs
• the new heating system has not been funded by the Energy Company Obligation (ECO)

An additional requirement for air-to-water and ground source heat pumps is that they must have a minimum seasonal coefficient of performance (SCOP) rating of 2.8.

For air-to-air heat pumps, they can only be installed in residential properties. 

Additional biomass boiler requirements 

Biomass boilers are eligible for a £5,000 voucher only. 

Further eligibility requirements for biomass boilers are: • 

• they can only be installed in rural properties  
• the new biomass boiler must be capable of meeting the full space and water heating needs of the property on its own  
• they can only be installed in properties that are not, and have never been, connected to the gas grid
• cannot be installed in self-builds
• must have an emissions certificate to show they meet certain emissions standards for the scheme
• must replace all heat-generating components of the original heating system (where applicable, you may retain circulation pumps, solar thermal collectors, wood-burning stoves, and supplementary electric heaters, including immersion heaters)
• must not have been used prior to commissioning, except in limited circumstances, e.g. to dry out plasterwork during construction or renovation (for shared ground loops, a new heat pump can connect to an existing shared loop)
• must replace either a fossil fuel heating system or an electric heating system
• the property owner has not received another grant from public funds to cover any of the purchase or installation costs
• the new heating system has not been funded by the Energy Company Obligation (ECO)
• the property owner at the installation address will own the new biomass boiler after it is installed