ECO4 heating measures

ECO4 is a Great Britain-wide obligation on medium and large energy suppliers. It supports improvements to inefficient homes occupied by low-income, fuel-poor or vulnerable households, including insulation and some heating work.

It is not a pot of grant money that an eligible householder can claim. Ofgem is explicit that suppliers choose the projects, measures and level of funding. An offer may cover the full cost, but the household can be asked to contribute. Eligibility does not guarantee that any company will make an offer.

ECO4 remains active and applies to qualifying measures completed by 31 December 2026, as checked on 22 July 2026. The nine-month extension did not increase suppliers’ targets and was intended to allow an orderly close and remediation work, so the end date should not be read as a promise that new projects will remain available until the final day.

Who can be eligible

The property and the household are assessed together. ECO4 generally treats the least efficient homes, but tenure changes which ratings and measures qualify.

For a privately owned home, a household can qualify through the Help to Heat Group. The current benefit list includes Child Benefit, Pension Guarantee Credit, income-related Employment and Support Allowance, income-based Jobseeker’s Allowance, Income Support, Universal Credit, Housing Benefit and Pension Credit Savings Credit. Child Benefit has income caps, and the detailed evidence rules sit in Ofgem’s live guidance.

Receipt of the relevant Warm Home Discount core-group rebate can also provide a Help to Heat route for the applicable scheme year.

ECO4 Flex lets a participating local authority, the Welsh or Scottish Government, or an energy supplier refer some households outside the standard benefit route. The main consumer criteria published by Ofgem at 22 July 2026 include:

combined gross annual household income below £31,000
a severe or long-term cardiovascular, respiratory, mobility or immunosuppression condition made worse by a cold home
persistent fuel debt supported by an energy supplier
repeated inability to keep a prepayment supply connected because of financial hardship

There are several Flex routes and the referring body must apply its current statement and evidence rules. A council declaration is a referral, not a guarantee that a supplier will fund the project.

Social housing let below market rent has a separate property route. Homes rated E, F or G can receive specified measures including insulation, first-time central heating, renewable heating and district-heating connections. A D-rated social home is much more restricted and does not have the same general heating options.

Owner-occupied homes can generally start in SAP bands D to G. Private rented homes are normally limited to E, F or G and must receive one of the scheme’s qualifying package measures. The tenant’s circumstances, rather than the landlord’s, establish household eligibility, and the landlord must consent.

These are screening rules, not a substitute for the retrofit assessment and supplier decision.

Heating work ECO4 can support

The eligible-measures table is non-exhaustive, and the exact package depends on the existing heating, tenure, energy rating and assessment. The main heating routes are:

An inefficient heating-system upgrade. In an owner-occupied on-gas home, an old non-condensing boiler can be upgraded to efficient heating. A working condensing boiler is not treated as inefficient simply because a newer model is available.

Repair or replacement of broken efficient heating. A condensing boiler that has broken down can be repaired where that is economical. Replacement can qualify where it cannot be economically repaired, subject to the scheme’s caps and property rules. Boiler repair and like-for-like replacement are generally not available in the private rented sector under ECO4.

First-time central heating. This is a new wet central-heating system for a home that has not previously had one. The legal definition also considers whether the property contained a working efficient electric storage heater during the relevant ECO4 period. “No boiler at present” is not enough to establish eligibility.

Renewable heating. Air source and ground source heat pumps can qualify. Low-carbon microgeneration work must use the appropriate MCS-certified installer. In an off-gas home, a hydronic heat pump is the first heating option the scheme requires the designer to consider.

Electric heating. High heat-retention storage heaters and certain electric-heating upgrades can qualify, but the off-gas hierarchy places them behind hydronic heat pumps and eligible district-heating or rural biomass options. Electric boilers cannot currently be installed under ECO4 because there is no applicable PAS 2030 annex.

District-heating connection. A property can be connected to a qualifying heat network. Consumer-protection and technical rules apply, and shared-ground-loop heat-pump arrangements are treated specially.

Heating controls. Eligible controls include thermostatic radiator valves, programmer and room-thermostat combinations, smart thermostats, time-and-temperature zone control and compensation controls. Existing controls and the assessment method affect which measure can be claimed.

Solar PV can appear in an ECO4 whole-home package, but the rules do not require solar panels with every heat pump. An installer presenting its own preferred bundle as a universal ECO4 rule is overstating the scheme.

The on-gas and off-gas rules

For an on-gas home, the present system determines the route. A sound efficient system cannot simply be exchanged for another of the same kind. Renewable heating, district heating or eligible controls may still be possible. An inefficient system can be upgraded, while a broken efficient system follows the repair and replacement tests.

For ECO4 purposes, off-gas status is tied to the property’s gas connection at the scheme’s reference date and supported by evidence; it is not decided only by the fuel the householder happens to use today.

The off-gas hierarchy works broadly as follows:

Consider a hydronic heat pump, including a qualifying heat-pump district-heating connection.
If that is not possible, consider another eligible district-heating connection or, for a rural property, a wood-fuel biomass system.
Only if the higher options are not possible, consider the eligible electric-heating, storage-heater or repair routes.

“Not possible” has a defined evidential meaning. It can arise from technical impracticability, a scheme exemption or the recommendations in the project’s improvement-options evaluation. It is not enough for an installer or householder simply to prefer a lower option.

ECO4 cannot install new mains-gas, oil, LPG, biofuel or coal heating in an off-gas home. Certain repairs to existing oil, LPG or biofuel systems can be eligible within the hierarchy. Coal heating is excluded.

Whole-house assessment and insulation first

ECO4 uses the PAS 2035 domestic retrofit process. A pre-retrofit assessment establishes the home’s starting rating and condition, then the project is designed around the building rather than a single advertised product.

The normal minimum improvement is:

a D- or E-rated home reaches at least C
an F- or G-rated home reaches at least D

The scheme has defined exemptions and project-scoring rules, so this is not a promise that every home will receive enough work to show that final EPC band in every circumstance.

Heating work is also subject to minimum insulation preconditions. For a D-rated home receiving heating other than first-time central heating or a district-heating connection, at least one eligible roof, wall, party-wall or floor insulation measure normally has to be installed in the same project unless the relevant insulation is already present or exempt.

An E-, F- or G-rated home receiving heating, and a D-rated home receiving first-time central heating or a district-heating connection, must normally have all exterior-facing cavity walls and the loft or roof insulated. That can be achieved through new work, qualifying pre-existing insulation, documented exemptions or a combination. Pre-existing insulation must meet the scheme’s standard; its mere presence is not enough.

Applying and assessing an offer

The household can contact any obligated supplier, even if it buys energy from someone else. A participating local authority or devolved administration may provide the Flex route. There is no central consumer application to Ofgem.

Before agreeing:

Confirm who the obligated supplier is and who will be the Retrofit Coordinator and installer.
Check the installer in the TrustMark register and verify the relevant MCS, Gas Safe or OFTEC registration for the proposed work.
Read the retrofit proposal and ask why each measure is included, what alternatives were assessed and how running costs are expected to change.
Obtain the written contract, the full price and any required contribution before work begins.
Check what happens if the supplier withdraws funding, a survey changes the package or enabling work is discovered.

ECO4 funding for a measure cannot simply be blended with funding for that measure from another government scheme such as the Boiler Upgrade Scheme. Separate work at the same property may need to take place before the ECO4 project starts or after the whole project is complete. Get the proposed funding split confirmed in writing.

Documents and protection

Installers are not “Ofgem approved”. Most ECO4 work must be delivered by a TrustMark-registered business, with the relevant technical certification as well. Registration is a check to perform, not a guarantee that every proposal is suitable.

Keep the contract, assessment, improvement plan, privacy notice, design, invoices, commissioning information, guarantees, warranties and post-installation declaration. Sign the customer-and-installer completion declaration only after the work is complete and you are satisfied that it accurately describes what was installed.

Ofgem’s current consumer guidance requires at least a two-year warranty for a boiler or electric storage heater replaced or upgraded under ECO4, and at least one year for a repair. Other TrustMark-delivered ECO measures carry their applicable guarantees and protections.

If a problem arises, follow Ofgem’s ECO complaints route: gather the installation date, installer, contract and guarantee, then use the TrustMark process and contact the installer and relevant scheme or guarantee provider. Ofgem can sometimes identify the recorded installer or funding supplier through a subject access request, but it does not resolve the householder’s installation contract itself.