Boiler Grants and Funding for London Homeowners and Landlords

Setting Expectations: What Government Schemes Cover

The most important thing to understand about boiler grants and funding in 2025 is that the UK government's primary funding schemes do not provide grants for like-for-like gas boiler replacement. The policy direction since 2022 has been to fund the transition away from gas heating — to heat pumps, biomass, and insulation — rather than to subsidise continued investment in gas infrastructure.

This means a homeowner whose gas boiler has failed and who wants to replace it with a new gas boiler will not receive a government grant for that replacement. The decision to replace like-for-like with gas is entirely legitimate and legal, but it will be self-funded.

What government schemes do exist are targeted at specific groups (fuel-poor households, low-income residents) or at specific technologies (heat pumps, biomass, insulation). The details of each are below.

Boiler Upgrade Scheme (BUS)

The Boiler Upgrade Scheme, administered by Ofgem, provides grants to replace existing gas or oil boilers with low-carbon alternatives:

• Air source heat pump: £7,500 grant toward the installed cost
• Ground source heat pump (including water source): £7,500 grant
• Biomass boiler: £5,000 grant (in rural areas only where mains gas is not available)

The grant is paid directly to the installer, reducing the cost to the homeowner. The homeowner does not need to apply directly — the Microgeneration Certification Scheme (MCS)-accredited installer applies on the homeowner's behalf.

Eligibility conditions:

• The property must be in England, Scotland, or Wales
• The property must have an EPC (Energy Performance Certificate) with no outstanding recommendations for loft or cavity wall insulation — you must address insulation before claiming
• One application per property
• Available to homeowners and landlords (for eligible properties)

For London specifically: air source heat pumps are technically feasible in most London houses and many flats (with managing agent consent for external unit installation). However, the cost of an air source heat pump installed in London (typically £10,000–£16,000) means the £7,500 grant still leaves a significant gap compared to a gas boiler replacement (£2,000–£3,000). The BUS makes sense for those committed to low-carbon heating; it does not make sense as a cost-minimisation option.

ECO4 Scheme

The Energy Company Obligation 4 (ECO4) scheme requires energy suppliers (British Gas, EDF, Eon, etc.) to fund energy efficiency improvements in the homes of low-income and fuel-poor households. ECO4 can cover:

• Boiler repair or replacement for households meeting the eligibility criteria
• Insulation (loft, cavity wall, solid wall)
• Heat pumps and other low-carbon heating

Eligibility for ECO4:

• The household must be in receipt of certain benefits — Universal Credit, Pension Credit, Child Tax Credit, Working Tax Credit, Housing Benefit, or equivalent — or have an annual household income below a defined threshold
• The property must have an EPC rating of D, E, F, or G
• For boiler replacement specifically, the existing boiler must be beyond economic repair

ECO4 is one of the few schemes that can fund a gas boiler replacement, but it is strictly means-tested and the energy supplier (not the homeowner) decides what measures to fund. The scheme ends in March 2026.

To apply: contact your energy supplier directly or use the government's ECO4 referral service at gov.uk/energy-company-obligation.

Great British Insulation Scheme

The Great British Insulation Scheme (GBIS) provides funding for a single insulation measure per property — typically loft or cavity wall insulation. It is not directly relevant to boiler replacement but is worth noting: insulating the property reduces heating demand and makes any heating system (including a new boiler) more efficient and cheaper to run. GBIS eligibility is means-tested (similar to ECO4) but also has a broader group element for properties in Council Tax bands A–D with EPC ratings below C.

Mayor of London Warmer Homes

The Mayor of London operates the Warmer Homes programme, which provides energy efficiency improvements to low-income Londoners. Funded through the GLA and delivering through local authority referrals, Warmer Homes offers:

• Boiler replacement for eligible households
• Insulation measures
• Low-carbon heating systems

Eligibility is based on income and property EPC rating. London-specific eligibility criteria are slightly different from national ECO4 criteria — households that miss ECO4 eligibility may qualify through the London scheme. Contact your London borough council's housing team for a referral, or visit the Warmer Homes scheme page on the GLA website.

London Borough and Council Schemes

Several London boroughs operate their own energy efficiency schemes, sometimes in partnership with energy companies or housing associations. These are typically targeted at private rented properties or owner-occupied properties in specific fuel poverty risk areas. Schemes vary by borough and change frequently — contact your borough's housing or sustainability team to ask what is available. Boroughs with historically active schemes include Lewisham, Hackney, Islington, and Southwark.

Landlord Energy Efficiency Grants

There are no dedicated grants for landlords to replace gas boilers in rental properties. However, landlords with rental properties that have very low EPC ratings (F or G) may be able to access ECO4 funding if their tenants meet the income eligibility criteria. The tenant applies through their benefit entitlement; the landlord benefits from a funded energy efficiency improvement. This is worth exploring where tenants are in receipt of qualifying benefits and the property has poor energy efficiency.

Note that from April 2020, all new tenancies in England require a minimum EPC rating of E, and the government has proposed raising this to C by 2028 for rental properties. Landlords with F or G-rated properties need to improve energy performance regardless of whether funding is available.

What These Schemes Do NOT Cover

To be clear about realistic expectations:

• No grant for like-for-like gas boiler replacement for homeowners above the income threshold
• No grant for landlords replacing a gas boiler in a property where the tenant does not meet ECO4 income criteria
• No grant for partial upgrades (e.g., upgrading controls only, replacing the heat exchanger)
• No grant simply for having an old or inefficient boiler — the boiler must be broken and beyond economic repair for ECO4 purposes