Boiler Upgrade Scheme (BUS)

We get quite a few enquiries from customers about the latest government grant, so I thought I would put together a bit of a guide, and here it is:

Guide to the Boiler Upgrade Scheme

The Boiler Upgrade Scheme, or BUS for short, is a voucher grant scheme run by the British Government. It pays a one off grant of £5,000 towards the installation of a biomass boiler or Air Source Heat Pump (ASHP), or a £6,000 grant towards a Ground Source Heat Pump (GSHP). The installer applies for the grant and when the installation is finished and commissioned, the installation company redeems the voucher, so the customer has the amount of the grant taken off the bill.


  1. Residency:

    The householder must be a resident of England, Scotland, or Wales, and the property must be their primary residence.
  2. Boiler size:

    The boiler must be under 50kW output.
  3. Energy efficiency:

    The property must meet certain energy efficiency requirements, such as wall cavity insulation, if it’s a cavity wall or of a type of construction that can be filled with insulation. Their roof insulation must be up to current standards, 270mm of fibreglass or the equivalent. There are exemptions for listed buildings
  4. Boiler replacement:

    The householder must agree to replace their existing boiler with a more energy-efficient one, which is listed on the Product Eligibility List.
  5. Installer:

    The installation must be carried out by a qualified and certified installer who is registered with the Microgeneration Certification Scheme. (MCS Accredited)
  6. Application process:

    The installation company applies for the voucher on behalf of the customer. The householder is then contacted by BUS officials, who check the property meets the criteria and indeed whether the householder is aware the voucher has been applied for. The voucher last for 3 months if awarded.
  7. Cost contribution:

    The householder will most likely be required to make a financial contribution towards the cost of the new boiler and installation, depending on their circumstances and the level of funding available under the scheme.
  8. Other conditions:

    There are quite a few caveats for biomass boilers. They are not allowed a BUS voucher for biomass if your house is on the gas grid or has ever been connected to it, or if it’s classed as being within an urban area on the Office for National Statistics post code lookup. If it’s classed as A, B or C then it’s not eligible for biomass. Heat pumps are allowed in any area

This is not an exhaustive list, trust me there’s more, but these are the main points relating to BUS and biomass boilers.