What ECO4 actually funds in 2026
ECO4 is the fourth iteration of the Energy Company Obligation. It is not a discretionary grant pot the government hands out year-on-year — it is a statutory obligation placed on the larger UK energy suppliers to deliver a fixed amount of lifetime bill savings to fuel-poor households by paying for energy-efficiency measures in EPC band D-G properties. The scheme runs from 1 April 2022 until 31 December 2026, following a nine-month extension confirmed in Ofgem's ECO4 Delivery Guidance v4.0 (March 2026). Measures installed after that closure date will not count towards a supplier's obligation, which in practice means installers will stop accepting new applications in the autumn.
For heating, ECO4 will pay for the boiler or heating system, the internal pipework, the controls and thermostat, the radiators where the existing ones are unfit, the safe removal of the old system, and the final commissioning and certification. What it will not pay for is anything outside the property boundary — most importantly the gas-main connection if you are off the gas grid — and it will not replace a working A-rated condensing boiler simply because a homeowner wants a newer model. The SAP modelling needs to show a genuine band uplift for the measure to qualify.
The two eligibility gates
Every ECO4 conversion route has the same two gates. First, the household has to qualify. The benefits route on gov.uk's ECO4 page lists Universal Credit, Pension Guarantee Credit, Pension Savings Credit, Income Support, income-based JSA, income-related ESA, Child Benefit (subject to household-size thresholds) and Housing Benefit as the qualifying claims. If none of those apply, the LA Flex route lets a local authority refer you under its Statement of Intent; most English councils set the gross household income threshold around £31,000, some London boroughs run higher, and clinical vulnerability (a cold-aggravating condition such as COPD or moderate-to-severe heart failure) usually overrides the income test.
Second, the property has to qualify. EPC band D, E, F or G for owner-occupiers; E, F or G for privately rented homes; E, F or G for social housing. The EPC is the gate — if there is no lodged EPC, your installer will commission one before any other work starts, and the modelled measures have to lift the property towards band C. Northern Ireland is out of scope for ECO4; households there use the Affordable Warmth scheme administered through the Department for Communities instead. All of this is administered by Ofgem and recorded against the installer's TrustMark licence — see ECO4 Guidance: New Measures and Products for the canonical scheme rules.
Non-condensing → condensing replacement
This is by volume the most common ECO4 conversion. A non-condensing boiler — anything pre-2005 in most cases, anything pre-2007 in stubborn ones — typically runs at 70-80% net efficiency. A new A-rated condensing boiler runs at 92-94%. On a 20,000 kWh annual gas demand that gap is worth roughly £200-£400 in cash terms at the April 2026 price cap, before you account for the smart-controls bundle that usually goes in alongside.
ECO4 will fund the replacement when the existing unit is either broken (the easier case) or modelled by your retrofit assessor as inefficient enough to drag the EPC down. Your assessor produces a PAS 2035 retrofit plan; your installer holds PAS 2030 certification for boiler measures; the work is lodged on the TrustMark Data Warehouse before any funding claim is made. If your quote doesn't reference all three of those (PAS 2030, PAS 2035 retrofit plan, TrustMark lodgement), it is not a compliant ECO4 install and you should refuse it.
A practical note: the scheme will not fund a like-for-like swap where your existing boiler is already condensing and merely old. "Old condensing" is not "non-condensing" — the badge-plate efficiency rating is what matters, and your installer will photograph it as part of the pre-installation declaration Ofgem requires on every job.
Oil or LPG → mains gas
This is the route where homeowners get the biggest sticker shock — in the right direction. An oil-fired heating system burns kerosene at roughly 9p per kWh delivered; mains gas at the April 2026 price cap sits closer to 6p per kWh. For a 20,000 kWh property that is around £600 of fuel cost out, before you account for the loss of oil deliveries (£800-£1,200 per fill), specialist annual servicing (£150-£200) and the risk of fuel theft from outdoor tanks.
ECO4 will fund the new gas boiler, the internal pipework, the meter installation paid to your supplier, the safe drain-down and removal of the oil tank, and the ground reinstatement after the tank comes out. What it does not fund is the connection from your gas meter to the gas main, which is paid to whichever Gas Distribution Network operates in your area — Cadent covers most of England, SGN covers Scotland and Southern England, Wales & West Utilities covers Wales and the South-West, Northern Gas Networks covers the North-East. Expect £500-£800 for a short connection of about 10m, £1,000-£1,200 for a 20m run, and £1,500-£2,500+ where the property sits 50m or further from the main.
Two warnings worth taking seriously. First, if the gas connection is genuinely uneconomic — long runs over private land, no neighbouring connections — your assessor will normally recommend an air-source heat pump under the same ECO4 envelope rather than chase the connection. Second, do not commit to the boiler order before the GDN quote is in writing; the connection cost determines whether the overall conversion still pencils out.
Electric storage heaters → gas central heating (FTCH)
In the trade this is called First-Time Central Heating, even though the property usually does have some form of heating already. The legal definition that matters: there is no central wet system, just a set of electric storage heaters or panel heaters running off an Economy 7 / Economy 10 tariff. FTCH is one of the highest-scoring measures under ECO4's points table — a property going from storage heaters to a gas combi typically jumps two EPC bands in a single intervention, which is why Ofgem's measure-uplift table treats it favourably for suppliers chasing their obligation.
The work itself is substantial: gas connection (if needed), full system install including boiler, hot-water cylinder where a system or regular boiler is fitted, radiators in every room, programmable controls, removal of the old storage heaters, and certification. ECO4 covers all of that inside the property boundary. Disruption is real — expect three to five days of installers on site and one cold night if the work happens in winter.
A nuance the policy gets right: a property using electric storage heaters but already on the gas main is the strongest candidate of all, because the GDN cost falls away. A property using storage heaters and off-gas may end up routed to a heat pump instead — the SAP modelling drives the choice, not the homeowner's preference. Either way, the running-cost gap is dramatic: on a 12,000 kWh annual heat demand, a switch from peak-tariff electric storage at 30p per kWh to a modern gas combi at 6p per kWh saves on the order of £2,000 a year before any insulation top-up.
Back boiler removal
A back boiler is the gas heater hidden behind a living-room gas fire — common in three-bed semis built between roughly 1965 and 1985, and almost always paired with a hot-water cylinder upstairs. They are functional, but they are large, single-stage, and run at low efficiency. ECO4 funds back-boiler removal as part of a wider system upgrade, not as a standalone measure: the homeowner ends up with a modern combi (or sometimes a system boiler where the cylinder stays) installed elsewhere in the property, the back boiler decommissioned, the fire surround removed or rebuilt to a finish, and the chimney flue capped to building-control standards.
Two practical notes. First, the chimney work isn't optional — leaving the flue uncapped is a building-regulations breach, and your installer will price it into the job. Second, this is one of the few measures where the homeowner gets a visible aesthetic gain alongside the energy saving, because the old fireplace usually comes out completely. Plan for the cosmetic finish — paint, plaster, hearth removal — to take a couple of weeks beyond the boiler install itself.
Combi ↔ system / regular boiler swaps
A combi-to-system swap (or system-to-combi) on its own is rarely fundable under ECO4. The scheme cares about the efficiency uplift, not about format preference — if you already have a working condensing combi, the fact that you have run out of hot-water capacity isn't an ECO4 problem. There are two exceptions where this route does open up. One: the existing boiler is non-condensing or broken, in which case the SAP modelling already qualifies you for a replacement and the format change happens incidentally as part of the install choice your engineer makes for the property's hot-water demand. Two: a tied measure — adding solar PV with an immersion divert, or a heat-pump cylinder — makes a system layout meaningfully more efficient than the existing combi, in which case the system-format change rides on the back of the tied measure.
In short: if you came to this page hoping ECO4 would pay for a combi-to-system swap because your family of five keeps running out of hot water, the honest answer is no, but a private install of a system boiler is usually £2,500-£3,500 fitted, and you keep the option to apply for ECO4 again later if your circumstances change.
How to apply
The end-to-end path is the same for all five routes. Run the eligibility check first — both the benefits gate and the EPC gate — through our eligibility wizard or by calling +44 7375 868046. If you pass, your installer commissions a retrofit assessment (PAS 2035), produces a recommended measures plan, and quotes the work. The installer must be PAS 2030 certified for the measure being installed and the job must be lodged on the TrustMark Data Warehouse — both checks are non-negotiable. Installation typically lands two to six weeks after sign-off, with longer windows where a GDN connection is part of the scope. Final commissioning, Gas Safe certification and the EPC re-lodge close the loop.
For households who don't pass the benefits gate but think LA Flex applies, the route goes via your local authority's energy team — most councils publish their Statement of Intent and a simple form on their housing pages. The LA Flex council checker on this site lists which councils currently take new applications and their income thresholds.
FAQs
Does ECO4 fund every type of boiler conversion?
No. ECO4 funds heating upgrades that move a property from EPC band D-G towards a higher band. The five routes covered here — non-condensing to condensing, oil to gas, electric storage heaters to gas central heating, back boiler removal, and combi/system swaps — all qualify when the existing system is broken or genuinely inefficient and the modelled SAP uplift meets Ofgem's minimum. A working A-rated condensing boiler will not be replaced.
When does ECO4 close?
The scheme has been extended and now runs until 31 December 2026. Ofgem's ECO4 Delivery Guidance v4.0 (March 2026) sets the closure date and confirms measures must be installed by then to qualify. There is no confirmed successor scheme as of May 2026; the consultation on what follows ECO4 is still open.
What benefits qualify me for ECO4?
Per gov.uk, the qualifying benefits are: Universal Credit, Pension Guarantee Credit, Pension Savings Credit, Income Support, income-based Jobseeker's Allowance, income-related Employment and Support Allowance, Child Benefit (subject to household-size thresholds) and Housing Benefit. If you don't claim any of those, the LA Flex route lets your local authority refer you based on a Statement of Intent — most councils set the income threshold around £31,000.
If I'm off the gas grid, will ECO4 still pay to connect me?
ECO4 will pay for the boiler, the internal pipework, the controls, and the safe disposal of your old oil tank or storage heaters. The connection from your meter to the gas main is paid to your Gas Distribution Network (Cadent, SGN, Wales & West Utilities or Northern Gas Networks) and is not part of ECO4. Expect £500 for a short connection up to £2,500+ for properties 50m+ from the main. Some LA Flex schemes top this up; ask before you commit.
Is a heat pump a better option than an ECO4 gas boiler?
For a home that's already well insulated and on a low electricity tariff, an air-source heat pump is often the right long-term choice — and ECO4 can fund one if the SAP modelling supports it. For a draughty Victorian terrace on standard tariffs, a condensing gas boiler with insulation top-ups normally produces a faster bill drop. The honest answer depends on the SAP assessment your installer runs — there is no universal winner.
Will ECO4 cover the work if I rent privately?
Yes, with two conditions. You personally meet the benefits or LA Flex route, and your landlord signs the consent form your installer provides. The landlord can't be charged and can't raise your rent because of the upgrade. Private rental properties must be at EPC band E-G (rather than D-G for owner-occupiers) per the ECO4 rules.
Where does my installer have to be registered?
Every ECO4 installation must be lodged on the TrustMark Data Warehouse and the installer must hold PAS 2030 certification for the measure being installed. If your quote names no TrustMark licence number and no PAS 2030 scope, the work cannot be funded under ECO4 — walk away.
Sources cited
- Ofgem — ECO4 Delivery Guidance v4.0 (March 2026) — scheme closure date, supplier obligation, measure rules.
- gov.uk — Energy Company Obligation (ECO4) — qualifying benefits, EPC band rules, owner/landlord routes.
- Ofgem — FAQs for domestic consumers and landlords — LA Flex Statement of Intent, tenant rights, landlord consent.
- Ofgem — ECO4 & GBIS Eligibility and Pre-Installation Declaration v1.1 (December 2025) — the declaration form your installer must complete before work begins.
- Ofgem — ECO4 Guidance: New Measures and Products — measure types, including FTCH and fuel switch.