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

To apply for a grant on behalf of a property owner, your business must be certified to install the relevant technology with the Microgeneration Certification Scheme (MCS). 

Property eligibility

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

• (retrofits only) have an existing fossil-fuel or electric heating system that is being replaced by the BUS-funded installation 

Properties cannot be: 

• 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 

The following requirements apply wherefor an installation is installed in a retrofit property. Requirements that apply to retrofit installations include: 

• the BUS-funded installation must replace an existing fossil-fuel or electric heating system must be replaced by the BUS-funded installation,
• where the property has a valid Energy Performance Certificate (EPC), the certificate number must be provided. Where a property does not have a valid EPC, installers will be asked to provide alternative evidence to demonstrate eligibility. 

Requirements for eligible self-builds 

Properties are considered as eligible self-build 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 

Eligible technologies

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 and must not requested or accepted payment of this value. Failure to do so may lead to the rejection of a voucher application or revocation of a voucher. 

Heat pump 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 will be commissioned no more than 120 days prior to the voucher application being properly made.
• the new heat pump or biomass boiler meets 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 will 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 will 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 will only provide heating to the property being applied for (and any ‘related properties’ that the owner or occupier can use such as an annex or swimming pool).)
• the new heating system will 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 will 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 will not be a hybrid system that combines a heat pump with fossil fuel heating.
• the new heating system will 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 heat pump after it is installed 

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 

Biomass boiler requirements 

In addition, biomass boilers: 

• can only be installed in rural properties
• the new biomass boiler will be capable of meeting the full space and water heating needs of the property on its own
• 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