You may be wondering if you can get help paying for a new boiler. The cost of a new gas boiler installation in the UK in 2026 ranges from £1,500 for a basic combi swap to £4,500 for a system boiler with a hot water cylinder (Energy Saving Trust, 2026).
Several government grants can cover the full cost of a new boiler or heating system, but eligibility is strictly based on your income, benefits, and property’s energy rating. The main grant for a free boiler replacement is the Energy Company Obligation Phase 4 (ECO4), which can fund up to 100% of the cost for households on qualifying means-tested benefits.
Replacing a boiler costs between £1,500 and £4,500, but grants can cover up to 100% of the cost for eligible households
The average cost of a new gas boiler installation in the UK in 2026 ranges from £1,500 for a basic combi swap to £4,500 for a system boiler with a hot water cylinder (GOV.UK Boiler Upgrade Scheme page, updated February 2026).
The Boiler Upgrade Scheme (BUS) offers a flat grant of £7,500 towards an air source heat pump, which can replace a boiler entirely (GOV.UK Boiler Upgrade Scheme, 2026). The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The grant amount depends on your property type, existing heating system, and household income, not all applicants receive the full £7,500.
ECO4 is the main grant programme for free or heavily subsidised boiler replacements
ECO4 (Energy Company Obligation Phase 4) runs from April 2022 to March 2026 and is the largest UK household energy-efficiency scheme (Ofgem ECO4 programme overview, 2026). Eligibility requires the household to receive at least one qualifying benefit: Child Tax Credit, Working Tax Credit, Pension Guarantee Credit, Income Support, Income-based Jobseeker’s Allowance, Income-related Employment and Support Allowance, Housing Benefit, Universal Credit, or Pension Credit Savings Element (GOV.UK ECO4 eligibility page, 2026).
The scheme only covers boiler replacements if the existing boiler is broken beyond repair or at the end of its serviceable life, it does not fund upgrades to working boilers (Ofgem ECO4 installation rules, Section 3.2, 2026). The property must have an Energy Performance Certificate (EPC) rating of D, E, F, or G to qualify for a boiler replacement under ECO4 (Ofgem ECO4 guidance, EPC requirements, 2026). The scheme is delivered through your energy supplier, you cannot apply directly to Ofgem; you must contact your supplier or an approved installer.
The Boiler Upgrade Scheme only covers heat pumps, not boiler replacements, but it is the main grant for off-gas-grid homes
The Boiler Upgrade Scheme (BUS) provides a flat £7,500 grant toward the installation of an air source heat pump or ground source heat pump (GOV.UK Boiler Upgrade Scheme page, updated February 2026). Eligibility requires the property to have an EPC rating of D or better, with no outstanding recommendations for loft or cavity wall insulation (DESNZ BUS eligibility criteria, 2026).
The grant is available to homeowners and self-builders in England and Wales only, Scotland and Northern Ireland have separate schemes (GOV.UK BUS regional eligibility, 2026). The property must not be on the mains gas grid, unless the existing heating system is electric or oil-based, homes on mains gas cannot claim BUS for a heat pump (DESNZ BUS guidance, Section 4, 2026). The installer must be MCS-certified (Microgeneration Certification Scheme) and registered with TrustMark to carry out the work (MCS installer database, 2026).
Quick numbers, grant amounts, eligibility thresholds, and property limits
| Grant programme | Maximum grant amount | Typical household cost after grant | Income/benefit eligibility | EPC rating requirement | Property type limit |
|---|---|---|---|---|---|
| ECO4 (boiler replacement) | Up to 100% of cost | £0 | Must receive qualifying benefit | D, E, F, or G | Any property type |
| ECO4 (first-time central heating) | Up to 100% of cost | £0 | Must receive qualifying benefit | E, F, or G | Any property type |
| Boiler Upgrade Scheme (heat pump) | £7,500 flat | £2,000–£5,000 typical | No income test | D or better | Off-gas-grid homes only (or electric/oil) |
| Great British Insulation Scheme (insulation only) | Up to £1,500 | £0 | Must receive qualifying benefit | D, E, F, or G | Any property type |
| Home Upgrade Grant (off-gas-grid homes) | Up to £10,000 | £0 | Low-income households in off-gas-grid homes | D, E, F, or G | England only |
ECO4 boiler replacement covers up to 100% of cost for households receiving a qualifying benefit, with an EPC rating of D to G, on any property type. The Boiler Upgrade Scheme provides a flat £7,500 grant with no income test, but requires an EPC of D or better and is limited to off-gas-grid homes or properties with electric or oil heating. The Home Upgrade Grant offers up to £10,000 for low-income households in off-gas-grid homes in England, with an EPC of D to G (GOV.UK Home Upgrade Grant page, 2026).
You are not eligible for a free boiler if your income is above £31,000 or your EPC is A, B, or C
ECO4 has a strict income threshold: households with an annual income above £31,000 (single person) or £40,000 (couple or family) do not qualify, even if they receive a qualifying benefit (Ofgem ECO4 income thresholds, 2026). Properties with an EPC rating of A, B, or C are automatically excluded from ECO4 boiler replacement funding, regardless of benefit status (Ofgem ECO4 EPC requirements, 2026).
If you own a property with an EPC D or better and are not on benefits, you cannot claim ECO4 or GBIS for a boiler replacement, you must pay privately or use the Boiler Upgrade Scheme for a heat pump. Landlords are not eligible for ECO4 boiler grants unless the tenant is the benefit claimant and the property meets the EPC threshold (Ofgem ECO4 landlord eligibility, 2026). Second homes and holiday lets are not eligible for any of the main grant schemes (DESNZ property eligibility rules, 2026).
To verify your eligibility, check your EPC, benefit status, and installer certification in that order
Step 1: Find your EPC rating on the gov.uk EPC register, you need the report number from your EPC certificate (GOV.UK Find an energy certificate page, 2026). Step 2: Confirm you receive at least one of the qualifying benefits listed on the Ofgem ECO4 eligibility page, if you are unsure, contact your local Citizens Advice or Jobcentre Plus (Ofgem ECO4 benefit checker, 2026).
Step 3: If you are eligible, contact your energy supplier directly, they must offer you a free assessment under ECO4 obligations (Ofgem ECO4 supplier obligations, 2026). Step 4: For the Boiler Upgrade Scheme, the installer must be MCS-certified, check the MCS installer database online before signing any contract (MCS certified installer search, 2026). Step 5: If you are not eligible for any grant, the cheapest option is a like-for-like combi boiler swap from a Gas Safe registered engineer, expect £1,500–£2,500 for a standard installation (Gas Safe Register installation cost data, 2026).
