What the Boiler Upgrade Scheme Offers UK Homeowners in 2026
The Boiler Upgrade Scheme (BUS) provides UK homeowners with government grants of up to £7,500 to replace fossil fuel heating systems with low-carbon alternatives, primarily heat pumps and biomass boilers. Launched in May 2022 and extended through to 2028, the scheme has supported over 50,000 installations across England and Wales as of early 2026. It represents the government’s most direct financial intervention to help households decarbonise their heating, which accounts for roughly 17% of UK carbon emissions. If your home currently runs on a gas, oil, or electric storage heater system, the Boiler Upgrade Scheme is likely the single most valuable grant available to you right now.
How the Boiler Upgrade Scheme Works
The scheme is administered by Ofgem on behalf of the Department for Energy Security and Net Zero. It works through a voucher-based system, but unlike many grant programmes, you never handle the money directly. Here is how the process flows from start to finish:
- Eligibility check, your installer confirms your property and heating system qualify before any work begins.
- Installer application, your chosen MCS-certified (Microgeneration Certification Scheme) installer applies to Ofgem for a voucher on your behalf.
- Voucher issued, Ofgem issues a voucher, typically within a few days of a successful application.
- Installation completed, the installer fits your new heat pump or biomass boiler to MCS standards.
- Voucher redeemed, the installer redeems the voucher directly with Ofgem. The grant amount is deducted from your invoice automatically.
- You pay the difference, you only pay what remains after the grant has been applied.
This direct deduction model is a deliberate design choice. It removes the burden of upfront costs from homeowners and reduces the risk of fraud. The voucher is valid for 3 months from the date of issue, so once the application is approved, installation needs to happen promptly. Extensions are available in certain circumstances, such as equipment supply delays.
The scheme currently runs in England and Wales. Scotland operates its own equivalent programme, the Home Energy Scotland Grant and Loan scheme, which provides separate funding routes. Northern Ireland has distinct arrangements through the NI Renewable Heat Incentive legacy programme and successor schemes.
Boiler Upgrade Scheme Grant Amounts in 2026
Grant values were increased in October 2023 and remain at the following levels through 2026:
| Technology | Grant Amount | Typical System Cost Before Grant | Estimated Cost After Grant |
|---|---|---|---|
| Air source heat pump (ASHP) | £7,500 | £10,000 – £15,000 | £2,500 – £7,500 |
| Ground source heat pump (GSHP) | £7,500 | £20,000 – £35,000 | £12,500 – £27,500 |
| Biomass boiler | £5,000 | £10,000 – £19,000 | £5,000 – £14,000 |
These figures reflect average market rates across England and Wales in early 2026. Costs vary significantly by property size, existing infrastructure, and regional labour rates. The biomass boiler grant is restricted to rural properties not connected to the gas grid, which narrows its applicability considerably compared to heat pump grants.
How Much Does Boiler Upgrade Scheme Installation Cost in 2026
Understanding the full cost picture requires looking beyond the headline grant figures. Installation costs break down into several components, and the size of your home is one of the most influential factors.
| Property Type | Recommended Heat Pump Size | Total Installed Cost (Before Grant) | Total Cost After £7,500 BUS Grant |
|---|---|---|---|
| 1–2 bedroom flat or small terrace | 5–7 kW | £8,000 – £11,000 | £500 – £3,500 |
| 3-bedroom semi-detached | 8–10 kW | £11,000 – £14,000 | £3,500 – £6,500 |
| 4-bedroom detached | 10–14 kW | £13,000 – £18,000 | £5,500 – £10,500 |
| Large detached or listed property | 14–20 kW | £16,000 – £25,000 | £8,500 – £17,500 |
Additional costs that are not always quoted upfront include radiator upgrades (larger radiators improve efficiency with a heat pump’s lower flow temperatures, costing £150–£400 per radiator), hot water cylinder installation if your home currently has a combi boiler (£800–£1,500), electrical upgrades to your consumer unit (£500–£1,200 in some cases), and scaffolding for outdoor unit positioning (£300–£600). Always request a fully itemised quote that covers all ancillary works.
VAT on heat pump installations is currently charged at 0%, a reduction from the standard 20% that was introduced in April 2022 and applies to all energy-saving materials and installations. This saving alone can amount to £2,000–£3,000 on a typical installation and stacks on top of the BUS grant.
Who Is Eligible for the Boiler Upgrade Scheme
Eligibility criteria are more straightforward than many government schemes, but there are specific conditions you need to meet before your installer can apply.
- Property location, the property must be in England or Wales.
- Property type, must be an existing home. New builds are excluded. Self-build properties may qualify in certain circumstances.
- Current heating system, you must be replacing a fossil fuel system (gas, oil, LPG) or an electric storage heater system. You cannot use the grant to replace an existing heat pump.
- EPC requirement, your property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft insulation or cavity wall insulation. If such recommendations exist, you must either complete that insulation work first or obtain a written technical assessment from an energy assessor confirming the improvements are not suitable for your property.
- MCS-certified installer, the installation must be carried out by an installer certified under the Microgeneration Certification Scheme. Using an uncertified contractor disqualifies you entirely.
- One grant per property, each property address can receive one BUS grant. The scheme is not income-tested, so it is open to all homeowners regardless of earnings.
The absence of income means testing is one of the scheme’s most distinctive features. Unlike the ECO4 Scheme, which targets low-income and fuel-poor households, the Boiler Upgrade Scheme is accessible to any homeowner in England or Wales meeting the technical criteria.
Benefits of the Boiler Upgrade Scheme
The financial and practical advantages of participating in the scheme extend well beyond the headline grant figure.
Lower running costs over time, a modern air source heat pump achieves a Coefficient of Performance (COP) of 3.0 or higher, meaning it delivers 3 units of heat for every 1 unit of electricity consumed. Even with electricity priced at approximately 24p per kWh in 2026, this efficiency level makes heat pumps cost-competitive with gas boilers for most households, and significantly cheaper than oil or LPG heating.
Carbon reduction, replacing a gas boiler with an air source heat pump typically reduces a home’s heating-related carbon emissions by 40–60%, depending on the home’s electricity grid carbon intensity and insulation levels. As the UK grid continues to decarbonise, this figure improves automatically over the lifetime of the system without any further action on your part.
Long system lifespan, heat pumps are built to last 20–25 years with proper maintenance, compared to the typical 10–15 year lifespan of a gas boiler. This means one heat pump installation may outlast two boiler replacements.
Increased property value, homes with EPC ratings of A or B now attract measurably higher sale prices and are increasingly preferred by mortgage lenders, some of whom offer green mortgage products at preferential rates. Installing a heat pump with BUS support can move a C-rated property to a B rating in many cases.
Summer cooling capability, some air-to-water heat pump systems can provide passive or active cooling in summer months. As UK summers become hotter, this functionality adds comfort value that a gas boiler simply cannot provide.
Energy security, moving away from fossil fuels reduces your exposure to volatile gas and oil markets. The 2021–2023 energy crisis demonstrated the risk that dependence on imported gas creates for household bills.
How to Choose the Right Technology Under the Boiler Upgrade Scheme
The scheme covers three technologies, and selecting the right one for your property requires honest assessment of your circumstances rather than defaulting to the most popular option.
Air source heat pumps are suitable for the widest range of properties. They extract heat from outdoor air, even at temperatures as low as -20°C, and work effectively in well-insulated homes with modern radiators or underfloor heating. They are the right choice for the majority of urban and suburban homeowners. The main limitation is that they require outdoor space for the external unit (typically 0.5–1 square metre of footfall), adequate noise separation from neighbouring properties, and they perform best in homes with an EPC rating of D or above.
Ground source heat pumps extract heat from the ground via buried loop systems or boreholes. They deliver a higher COP than air source (typically 3.5–4.5) and operate at steadier efficiency year-round since ground temperatures are more stable than air temperatures. However, they require either significant garden space for horizontal ground loops (typically 200–400 square metres) or a borehole (60–150 metres deep), which adds cost and planning considerations. They are well-suited to larger rural properties with space and budget to invest in the infrastructure.
Biomass boilers burn sustainably sourced wood pellets, chips, or logs. They qualify for the £5,000 BUS grant but are restricted to rural properties off the gas grid. They function similarly to conventional boilers in terms of the heat distribution system, making retrofitting simpler in some cases. However, they require storage space for fuel, regular ash removal, annual servicing, and a reliable local fuel supply chain. They are a pragmatic choice for rural homeowners who have oil heating and limited options for heat pumps due to property constraints.
When assessing which technology suits your home, consider these four factors in order: property insulation levels, existing heat distribution system (radiators, underfloor heating, or fan coil units), available outdoor or garden space, and your grid connection and electrical capacity. A reputable MCS-certified installer will carry out a full heat loss survey before specifying any system, be cautious of any installer who quotes without one.
Boiler Upgrade Scheme Installation, What to Expect
Understanding the installation process helps you plan practically and avoid surprises. A typical air source heat pump installation runs across two to three days, though complex retrofits or those requiring significant ancillary work can take up to five days.
Day 1, Survey and preparation work
Your installer begins with a detailed heat loss calculation for every room in your home (to BS EN 12831 standards). This determines the correct system size. Any preparatory electrical work, such as upgrading the consumer unit or running a dedicated circuit to the heat pump location, is typically completed on this day.
Day 2, Core installation
The external unit is positioned and secured, refrigerant pipework is run between the external and internal units, and the internal hydronic components (buffer tanks, hot water cylinder, control unit) are installed. The existing pipework is assessed and any necessary radiator upgrades are completed.
Day 3, Commissioning and handover
The system is charged with refrigerant, pressure-tested, and commissioned. Your installer will set up the control system and spend time walking you through optimal operation, including setting flow temperatures correctly (typically 45–55°C rather than the 70–80°C used by gas boilers) and programming weather compensation controls, which automatically adjust output based on outdoor temperature.
After installation, your installer must register the system with the MCS and provide you with the installation certificate, which is required to redeem the voucher with Ofgem. You should also receive a full handover pack including the manufacturer’s warranty documentation (typically 5–7 years for the heat pump unit itself, extendable to 10 years with manufacturer registration).
Grants and Funding That Work Alongside the Boiler Upgrade Scheme
The Boiler Upgrade Scheme does not exist in isolation. Several other funding streams can be combined or sequenced alongside it to reduce your total investment.
0% VAT on installation, as noted above, this applies automatically and saves 20% on the total installation cost. No separate application is needed; your installer should invoice at 0% VAT for qualifying works.
Smart Export Guarantee (SEG), if you pair a heat pump with solar PV panels, the SEG pays you for surplus electricity exported to the grid. Rates vary by energy supplier, but typically range from 4–15p per kWh exported. This combination allows your solar generation to offset heat pump running costs effectively.
ECO4 and the Great British Insulation Scheme, improving insulation before or alongside heat pump installation reduces the size of heat pump needed and lowers running costs. If your household qualifies on income grounds, ECO4 can fund insulation measures at no cost. The Great British Insulation Scheme offers broader eligibility for cavity wall and loft insulation. Completing this insulation work also resolves any EPC recommendations that might otherwise block your BUS application. Great British Insulation Scheme Guide, how to fund insulation improvements that support heat pump performance
Home Upgrade Grant (HUG2), this scheme targets low-income households in properties not connected to the gas grid (EPC D–G rated). It can fund heat pumps, insulation, and solar panels together. In some cases it provides more comprehensive funding than BUS for qualifying households, as it covers ancillary works that BUS does not.
Green mortgages and retrofit loans, several UK lenders now offer preferential mortgage rates for energy-efficient homes, and some banks offer unsecured green home improvement loans at reduced rates. These can bridge the gap between the BUS grant and the total installation cost.
It is worth checking eligibility for all applicable schemes before committing to installation. A good installer or an independent energy assessor can help map out the optimal funding combination for your specific situation.
Common Problems and How to Maintain Your Heat Pump
Heat pumps have fewer moving parts than combustion boilers and are generally reliable, but they do require specific maintenance practices to perform at their best over a 20-year lifespan.
Annual servicing is essential and typically costs £100–£200. A service includes checking refrigerant pressures, inspecting the fan and coil on the external unit, verifying control settings, and checking the system pressure and expansion vessel. Many manufacturers require annual servicing to maintain warranty validity, always check your warranty terms.
Common performance issues and their causes
- High electricity bills, most commonly caused by flow temperatures set too high (above 55°C) or weather compensation not being activated. A correctly configured system at 45–50°C flow temperature will use significantly less electricity than one running at 65–70°C.
- Noisy operation, some vibration noise from the external unit is normal, but excessive noise often indicates low refrigerant charge, a failing fan bearing, or loose mounting brackets. Have a qualified engineer inspect promptly.
- Icing on the external unit, mild surface frost is normal and the unit will defrost automatically. Persistent heavy icing suggests an airflow obstruction around the unit or a refrigerant issue.
- Rooms not reaching temperature, usually indicates the original heat loss survey was inaccurate, the system was undersized, or radiators are too small for the lower flow temperatures heat pumps use. Larger radiators or thermostatic radiator valve adjustments typically resolve this.
- System losing pressure, a slow pressure drop over months is normal; a rapid drop indicates a leak in the hydronic circuit that needs urgent attention.
Homeowner maintenance tasks that do not require a qualified engineer include clearing vegetation and debris from around the external unit (maintain at least 30cm clearance on all sides), checking and topping up system pressure if it falls below 1 bar (following your specific manufacturer guidance), and keeping the external unit clear of snow accumulation in winter. Do not attempt to tamper with refrigerant components, only F-Gas certified engineers may legally handle refrigerants in the UK.
Applying for the Boiler Upgrade Scheme, A Step-by-Step Checklist
The application process is managed by your installer, but understanding each step ensures nothing is missed and your voucher is secured without delay.
- Check your property has a valid EPC, if not, commission an EPC assessment (typically £70–£120).
- Review the EPC recommendations. If loft or cavity wall insulation is recommended and you have not had it installed, arrange this first or obtain a written technical assessment confirming it is not suitable.
- Get at least three quotes from MCS-certified installers. Verify certification at the MCS website (mcscertified.com) using the installer’s name or certificate number.
- Confirm with your chosen installer that they will handle the BUS voucher application before any work starts, the application must precede installation.
- Review and sign the installation contract. This ensures it clearly states the grant amount will be deducted from your invoice.
- Your installer submits the application to Ofgem and receives the voucher (typically within 2–5 working days).
- Installation is completed within the voucher validity period (3 months).
- Your installer registers the installation with MCS and redeems the voucher with Ofgem.
- You receive your final invoice showing the grant deducted, along with your MCS certificate and manufacturer warranty documents.
One practical note: during periods of high application volumes, Ofgem has occasionally paused new voucher applications while processing backlogs. This occurred briefly in 2023 and 2024. Monitor the Ofgem BUS portal status before planning installation timelines, particularly in autumn when demand peaks ahead of winter.
Is the Boiler Upgrade Scheme the Right Choice for Your Home in 2026
The Boiler Upgrade Scheme represents genuine value for most homeowners in England and Wales who are planning to replace their heating system in the next one to three years. With £7,500 available for heat pump installations, 0% VAT on top, and a scheme funded through to 2028, there is no financial advantage to waiting, and with gas boiler sales set to be phased out under current government policy frameworks, the direction of travel for home heating is clear.
The scheme is not a perfect fit for every circumstance. Homes with very poor insulation, structural constraints preventing external unit placement, or properties in shared ownership with complex lease arrangements may face hurdles. But for the majority of homeowners with a gas or oil boiler approaching end of life, the combination of BUS grant, 0% VAT, and long-term running cost savings makes a compelling financial case.
The most important single action you can take is to get a proper heat loss survey from an MCS-certified installer before committing to any system. A well-specified heat pump in a reasonably insulated home will perform quietly, efficiently, and reliably for two decades. A poorly specified one will disappoint. The scheme provides the funding; choosing the right installer ensures you benefit fully from it.
