The question of replacing an aging gas boiler carries different weight in 2026 than it did five years ago. With the Boiler Upgrade Scheme (BUS) extended through April 2028, householders now operate within a specific window of opportunity: significant government funding exists, but the technical requirements are strict, and the grant amounts vary considerably depending on which low-carbon technology you choose. Understanding exactly how much you can claim—and whether your property qualifies—requires navigating a system where the rules have tightened since the scheme’s initial launch.
What the Boiler Upgrade Scheme Covers in 2026
The Boiler Upgrade Scheme provides upfront grants toward installing low-carbon heating systems in England and Wales. Unlike the earlier Domestic Renewable Heat Incentive, which paid quarterly over seven years, the BUS operates as a one-time contribution deducted directly from your installation invoice. The scheme specifically targets properties moving away from fossil fuel heating—primarily mains gas, oil, or LPG boilers—toward air source heat pumps, ground source heat pumps, or biomass boilers in limited rural applications.
Crucially, the funding applies to the property, not the individual. This means landlords can utilize the scheme for rental properties, and there is no means-testing based on income. However, the installed system must meet minimum efficiency standards and be fitted by an MCS-certified installer who handles the grant application on your behalf.
Boiler Upgrade Scheme 2026: How Much Can You Get
For installations completed in 2026, the grant offers £7,500 for both air and ground source heat pumps, and £5,000 for biomass boilers in off-grid properties. These figures represent the increased rates announced in October 2023, designed to close the cost gap between traditional boiler replacements and heat pump installations. The amount never arrives as cash in your account; instead, your installer reduces the invoice total by the grant amount, then claims the funds from Ofgem.
The funding structure specifically excludes hybrid systems—combinations of heat pumps with fossil fuel boilers—unless installed under exceptional circumstances in specific heritage properties. For standard householders, you must commit fully to the low-carbon system to trigger the grant.
Air Source Heat Pump Grants
The £7,500 air source heat pump (ASHP) grant applies to systems with a maximum capacity of 45kW. For a typical three-bedroom home requiring a 10kW–13kW unit, this grant typically covers 30–50% of the total installation cost, depending on whether you require radiator upgrades or new hot water cylinders. The property must possess—or have installed—a valid Energy Performance Certificate (EPC) issued within the last ten years.
Ground Source Heat Pump Grants
Ground source heat pumps (GSHP) also qualify for the full £7,500 grant, despite historically costing significantly more than ASHPs to install. The equalization of grant rates between air and ground source systems reflects government attempts to encourage deeper retrofits where geological conditions permit. GSHP installations require sufficient garden space for horizontal trenching or access for vertical boreholes, typically 50–100 meters deep.
Biomass Boiler Funding
The £5,000 biomass grant applies only to properties located in rural areas without access to the gas grid. The boiler must burn wood pellets, chips, or logs from sustainable sources, and the property must demonstrate compliance with clean air standards. Urban properties, or those with mains gas connections, cannot access biomass funding under current regulations.
Who Actually Qualifies for the Grant?
You must own the property, possess a valid EPC with no outstanding insulation recommendations for loft or cavity walls, and use an MCS-certified installer. The insulation requirement often catches applicants unaware; if your EPC recommends loft insulation or cavity wall insulation that has not been installed, you must complete these measures first or secure an exemption certificate.
New-build properties generally do not qualify unless self-built by the owner-occupier. Social housing falls under separate funding streams, specifically the Social Housing Decarbonisation Fund. Second homes and holiday lets technically qualify if they meet the EPC standards, though the government has indicated potential tightening of rules for properties not occupied as primary residences.
The Application Process Step by Step
The BUS application process operates through your chosen installer, not through direct homeowner application. First, obtain quotes from at least three MCS-certified installers who will assess your property’s heat loss, radiator sizing, and electrical capacity. Once you accept a quote, the installer submits the grant application to Ofgem, including your property details and EPC information.
Ofgem typically processes applications within 30 days. Upon approval, the installer completes the work and reduces your final invoice by the grant amount. You then pay the balance. Keep all documentation, including the MCS certificate and commissioning certificate, as these may be required for future property sales or warranty claims.
If the application is rejected—commonly due to EPC insulation recommendations or incorrect property classification—you have 14 days to appeal or rectify the issue before the application expires.
Cost Realities Beyond the Grant
While the £7,500 grant is substantial, it rarely covers the full installation cost. Typical air source heat pump installations range from £12,000 to £18,000 for a standard home, meaning you should budget £5,000–£10,000 out-of-pocket after the grant. Ground source systems typically cost £20,000–£35,000, leaving a significant gap even after the grant is applied.
Additional costs often include: upgrading radiators to larger low-temperature models (£500–£2,000), installing hot water cylinders if converting from combi systems (£800–£1,500), and electrical supply upgrades (£300–£800). Some homeowners also require new pipework or the removal of old oil tanks, particularly in rural conversions from oil heating.
Comparing BUS to ECO4 and Other Funding
The Boiler Upgrade Scheme differs fundamentally from the Energy Company Obligation (ECO4), which targets low-income and vulnerable households. ECO4 provides fully funded insulation and heating measures for those receiving specific benefits, while BUS is available to all property owners regardless of income. You cannot stack BUS and ECO4 for the same installation—if ECO4 covers your heat pump, you cannot also claim the BUS grant.
Local authority grants occasionally supplement BUS funding, particularly in areas with air quality concerns. Check with your council’s sustainability team for additional incentives, which sometimes include interest-free loans covering the gap between the grant and total installation cost.
Verdict: Is the Scheme Worth the Effort?
The Boiler Upgrade Scheme 2026 represents genuine value if your property suits heat pump technology and you plan to remain in the home long enough to recoup costs through reduced energy bills. With electricity prices currently three times gas prices per kWh, the running cost equation favors well-insulated properties where heat pumps can achieve coefficients of performance (COP) above 3.0. In older, draughty homes, the upfront disruption of insulation upgrades combined with the installation cost may outweigh the grant benefit unless you are committed to decarbonization regardless of payback period.
For those with aging oil boilers in rural locations, the math often works decisively in favor of switching, particularly when combined with the biomass or heat pump grant. Mains gas householders should calculate carefully: the £7,500 grant covers roughly five to seven years of typical gas heating costs, meaning the investment only pays back if heat pump running costs drop below gas costs through improved efficiency or future energy price shifts.