ECO4 (Energy Company Obligation, fourth phase) is a UK government scheme requiring large energy suppliers to fund energy-efficiency improvements - including boiler replacements, central heating, and insulation - for low-income and vulnerable households. It is administered by Ofgem and funded by an obligation placed on energy suppliers above a defined customer threshold. ECO4 runs from April 2022 to March 2026 (extended several times) and a successor scheme is being designed by DESNZ.

Who is eligible for an ECO4 free boiler in 2026?

Eligibility is on two simultaneous tests. First, household must receive at least one qualifying benefit: Universal Credit, Pension Credit (Guarantee or Savings), Income Support, income-based Jobseeker's Allowance, income-related Employment and Support Allowance, Child Tax Credit, Working Tax Credit, Housing Benefit, or Pension Credit. Second, the home must have an EPC rating of D, E, F, or G (so well-insulated homes don't qualify). The property can be owner-occupied or private rented (with landlord consent for the latter).

How do I apply for an ECO4 free boiler?

Two routes. Route 1: contact your gas / electricity supplier directly (British Gas, EDF, E.ON Next, Octopus, OVO, Scottish Power, etc.) and ask about their ECO4 obligation programme. Route 2: use an ECO4 referral network (Boiler Grants, GBE-Help to Heat, free-boiler comparison sites). The installer carries out an EPC survey of your home (free to you), confirms eligibility, and applies on your behalf. Total time from application to install is typically 4-8 weeks.

UK 2026 / May 2026

ECO4 free boiler grant

The UK's main scheme for funding free or heavily subsidised boiler replacements for low-income and vulnerable households. Administered by Ofgem, funded by an obligation on large energy suppliers. Roughly 3.5 million UK households are estimated to be eligible.

Eligibility: the two tests

Test 1: Qualifying benefits

Household must currently receive at least one of:

Universal Credit
Pension Credit (Guarantee or Savings)
Income Support
Income-based Jobseeker's Allowance
Income-related Employment and Support Allowance
Child Tax Credit / Working Tax Credit
Housing Benefit
Child Benefit (with income thresholds)

Test 2: EPC rating

Home must have an EPC rating of D, E, F, or G. ECO4 priorities the worst-rated homes (F and G) which see the biggest energy savings from improvements.

Check your EPC at gov.uk/find-energy-certificate using your postcode. If you don't have one, the ECO4 installer carries out the survey as part of the application.

What ECO4 covers

Full boiler replacement (combi, system, or regular)
Central heating installation (where none exists)
Loft and cavity wall insulation
Heating controls and smart thermostats
First-time central heating systems (for homes currently without)
Underfloor insulation in some cases

Most ECO4 boiler grants cover the full cost of a like-for-like replacement including labour and certification. Some applications come with a small contribution from the household (typically GBP 0-GBP 500) depending on the installer's costing and supplier funding levels.

How to apply

Check eligibility against the two tests above (benefit + EPC D-G).
Choose one of two application routes:
- Direct via energy supplier: contact your gas or electricity supplier (British Gas, EDF, E.ON Next, Octopus, OVO, Scottish Power, etc.) and ask about their ECO4 programme. Each supplier has its own application process.
- ECO4 referral network: search for "ECO4 free boiler" or "boiler grants" and apply via a referral network. They aggregate applications and route to participating installers.
The installer carries out a free home survey including a new EPC assessment if needed.
Eligibility confirmed: installer schedules the work (typically 4-8 weeks from application to install).
Install carried out by a Gas Safe registered engineer with all standard certification.

Watch-outs

Cold-callers: ECO4 is targeted by cold-call scams. Don't agree to anything on the phone; verify any installer's Gas Safe registration at gassaferegister.co.uk independently.
Free EPC assessment: legitimate ECO4 installers provide this free as part of the application; never pay upfront for an EPC under an ECO4 context.
Contribution sometimes required: a small homeowner contribution (typically GBP 0-GBP 500) may apply depending on the installer / supplier. Always check upfront.
Boiler model often basic: ECO4 funding typically covers an entry-level brand (Baxi, Ideal Logic Max, similar). You can upgrade to a premium model by paying the price difference, but most households take the included unit.
Landlord consent: private rented sector tenants need the landlord's written consent. The landlord doesn't pay, but must agree to the work.

FAQ

What is ECO4?

The Energy Company Obligation phase 4 - a UK scheme requiring large energy suppliers to fund energy efficiency upgrades (including boiler replacements) for low-income households. Administered by Ofgem.

Who is eligible?

Household must receive a qualifying benefit (Universal Credit, Pension Credit, ESA, JSA, etc.) AND live in an EPC D-G property.

How do I apply?

Direct via your energy supplier, or via an ECO4 referral network. Installer carries out free home survey then schedules install (4-8 week typical timeline).

Is the boiler completely free?

Usually yes, though some applications include a small homeowner contribution (GBP 0-GBP 500). Always confirm upfront.

Will ECO4 continue past 2026?

ECO4 runs until 31 March 2026. A successor scheme (ECO5 or equivalent) is being designed by DESNZ but specifics are not yet published. Apply soon if eligible.

Not eligible for ECO4 but want low-carbon? See BUS GBP 7,500 heat pump grant. Otherwise see 0% finance options for spread-cost replacement.