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How to apply for the Boiler Upgrade Scheme?

In this guide, we're going to take you through the Boiler Upgrade Scheme application process and any FAQs you may have about the government scheme.
installer standing in front of a heat pump

What is the Boiler Upgrade Scheme?

The Boiler Upgrade Scheme (BUS) encourages homeowners in England and Wales to upgrade their fossil fuel boiler to a low carbon heating solution such as a heat pump. The proposed phase-out on the installation of fossil fuel appliances is 2035 which now includes LPG, oil and coal.

The £7,500 grant helps reduce the installation cost of your chosen low carbon heating system and is applied for through your MCS installer.

How can I apply for the Boiler Upgrade Scheme?

Application for the Boiler Upgrade Scheme grant is available only to MCS (Microgeneration Certification Scheme) accredited heat pump installers and is conducted through Ofgem, the Government’s scheme administrator.

If you believe you are eligible for the scheme, contact your local Vaillant MCS accredited installer. From here, the process will be as such:

1. Your installer will then further advise you on whether your proposed installation is eligible for a grant.

2. Your installer will then send you a quote for the installation which should include the deduction for the BUS grant.

3. Your installer will then provide your details to Ofgem, who will then contact you (via email) to confirm that you give consent for the installer to apply on your behalf.

4. Your installation will then be carried out and completed in line with both the industry standard and the requirements of the Boiler Upgrade Scheme.

5. The installer will then redeem the grant voucher and receive the grant following the full installation and commissioning. This voucher must be redeemed 3 months of the issue date for an air source heat pump or biomass boiler, and within 6 months of the issue date or 31st March 2028 (whichever is earlier) for a ground source heat pump.

Heat pump costs Watch the video 'Heat pump considerations and expected costs'

As heat pumps generate heat from the environment itself, the amount of energy required to create the necessary heating for your home is vastly reduced compared to other methods.

This video covers some of the typical heat pump installation considerations, including associated costs:


  • What do we do if we’ve already had the BUS application approved at the previous value?

    If you have already applied for your BUS voucher but not yet had your heat pump installed, you will only be eligible for the original amount of £5,000 for an air source heat pump and £6,000 for ground source heat pump. You are able to revoke your current voucher and reapply after Monday 23 October where you may be able to receive the higher value of £7,500.

  • What is a biomass boiler?

    Biomass boilers provide heating and hot water by burning natural materials such as wood pellets, wood chips, or logs. The term biomass refers to any organic materials which can be used as fuel, with the majority of biomass products that are used in domestic settings being wood based-for a ‘cleaner’ burn.

    In the UK, wood pellets are one of the most popular biomass fuel choices due because of their typically consistent size and ease of storage. These are typically made using forestry waste or by-products. Biomass boilers are typically significantly more expensive than traditional fossil fuel boilers and even most air source heat pumps, costing between £11000 and £25000.

    The Boiler Upgrade Scheme for biomass boilers is also only available in limited circumstances. Learn more via the government website.

  • Can I claim for other grants and funding?

    You can still apply if you’ve received separate funding for energy efficiency upgrades such as for insulation, or for doors or windows.

  • Can I replace an existing low carbon system with BUS funding?

    The Boiler Upgrade Scheme is only available to those replacing existing fossil fuel systems such as oil, gas or direct electric, and therefore funding is not available for those replacing existing low carbon systems.

  • What's the difference between the BUS and the RHI?

    The Domestic Renewable Heat Incentive (or RHI) was the preceding government scheme which ran until March 2022. This operated using a tariff-based system based on property efficiency and with payments being made to homeowners on a quarterly basis over the seven-year period following installation. This scheme therefore meant that homeowners were paying the full up-front cost with slow repayments, whereas the BUS has replaced this funding with an upfront flat rate discount.

    Unlike the RHI, the BUS also has more specific system eligibility criteria, requiring 100% of the heating and hot water load to be covered, excluding hybrid and heat-only systems, and requiring a minimum SCOP of 2.8 (as opposed to RHI’s minimum of 2.5).

  • Is this scheme affected by the VAT cut on energy saving materials?

    From 1st April 2022 until 31st March 2027, the Government has announced that a zero rate of VAT will apply to the installation of specified energy-saving materials (read more here). This will therefore cover the entire period of the BUS and will apply to any eligible materials.

  • What are the requirements for installers?

    All installers must be MCS accredited. Vaillant’s renewable partners are fully MCS accredited, find your local renewables installer here.