Rising energy bills and ageing, inefficient boilers have left millions of UK households facing a difficult choice: pay hundreds or even thousands of pounds for a new heating system, or continue living with a costly, unreliable one. Fortunately, the Free Boiler Scheme available through the government-backed ECO4 scheme exists to help. For eligible households, ECO4 can cover the full cost of a new, energy-efficient boiler — with no upfront payment and no loan to repay.
This guide explains everything you need to know about the Free Boiler Scheme under the ECO4 boiler grants in 2026: what the scheme is, who qualifies, what’s included, how to apply, and what to do if you don’t meet the standard criteria. We’ll also look at the scheme’s deadline and what might replace it once it ends.
Read more:Comment calculer un pourcentage pondéré – Formule et exemples pratiques
What Is the ECO4 Scheme
ECO4 stands for the fourth phase of the Energy Company Obligation, a UK government initiative that requires large energy suppliers — including British Gas, EDF, E.ON, Octopus Energy, and others — to fund energy efficiency improvements in the homes of low-income and vulnerable households. It is not a state benefit paid in cash; instead, it’s an obligation placed on energy companies, who fund the work directly through approved installers.
ECO4 focuses on improving the least energy-efficient homes in the country, targeting properties with poor Energy Performance Certificate (EPC) ratings — typically bands D, E, F, and G. The scheme’s goal is to lift these properties by at least two EPC bands through a combination of insulation and heating upgrades, reducing both fuel poverty and carbon emissions.
Unlike some earlier obligation schemes that focused narrowly on one measure, ECO4 takes a “whole-house” approach. This means that if you qualify, you may not simply receive a new boiler — you might also be offered loft insulation, cavity wall insulation, or other measures alongside it, since a more efficient home reduces the risk of heat loss even after a boiler upgrade.
What ECO4 Can Cover
Depending on your property’s needs and your installer’s assessment, ECO4 funding can go towards:
- Replacement of an old, broken, or inefficient boiler with a new A-rated condensing boiler
- First-time central heating installation for homes that have never had it
- Air source heat pump installation as a low-carbon alternative to a gas boiler
- Loft insulation
- Cavity wall insulation
- Solid wall (internal or external) insulation
- Underfloor insulation
- Room-in-roof insulation
- Solar PV panels in some cases
- Heating controls, such as thermostatic radiator valves and smart thermostats
Importantly, whether you receive a straightforward boiler swap or a package of several measures depends on a home assessment carried out by a qualified surveyor. ECO4 is not a “pick and choose” scheme — the improvements offered are based on what will most effectively raise your property’s energy efficiency.
Who Is Eligible for an ECO4 Boiler Grant
Eligibility for ECO4 is based primarily on two things: whether you (or someone in your household) receive certain means-tested benefits, and the energy efficiency rating of your property. There is also a secondary route — known as LA Flex — for people who don’t receive qualifying benefits but are still considered vulnerable to cold-related health risks or fuel poverty.
1. Qualifying Benefits Route
You are likely to qualify for ECO4 if you or someone living in your household receives one or more of the following benefits:
- Universal Credit
- Pension Credit (Guarantee Credit)
- Income-based Jobseeker’s Allowance (JSA)
- Income-related Employment and Support Allowance (ESA)
- Income Support
- Working Tax Credit
- Child Tax Credit (subject to an income threshold)
- Housing Benefit
- Warm Home Discount Scheme rebate (in some circumstances)
Some benefits, such as Child Tax Credit, come with an income cap — households need to fall under a specific annual income threshold to qualify. Because these thresholds and rules can be adjusted, it’s worth using an ECO4 eligibility checker or speaking to an approved installer to confirm your specific position rather than relying on assumptions.
2. Property Requirements
Alongside the benefits test, your home typically needs to have a poor EPC rating — usually D, E, F, or G — to qualify for support. Homes already rated A, B, or C are generally considered efficient enough that they fall outside the scheme’s priority group, although exceptions can apply depending on the specific measure being installed. Properties with an F or G rating are often given priority, since these are the least efficient homes and the ones ECO4 is specifically designed to help.
If you don’t know your property’s current EPC rating, you can look it up for free using the official EPC register, or a participating installer can check it for you as part of the eligibility process.
3. LA Flex — For Households Without Qualifying Benefits
Not everyone who needs help with their heating bills is on a qualifying benefit. Recognising this, the government allows local authorities to set their own additional eligibility criteria under a mechanism called LA Flex (Local Authority Flexible Eligibility).
Each council can define its own criteria for who counts as vulnerable or at risk of fuel poverty in their area. Common examples of households that qualify through LA Flex include:
- Low-income working households who don’t receive means-tested benefits (for example, nurses, teaching assistants, retail or hospitality workers)
- Households with a combined income below a locally set threshold
- Residents with a long-term health condition worsened by cold or damp housing, such as respiratory or cardiovascular conditions
- Households containing children under five, elderly residents, or disabled residents
- People recently referred by a GP, health visitor, or social prescriber due to cold-related health risks
Because LA Flex criteria differ from one council to another, it’s worth contacting your local authority directly, or asking an installer to check whether your council participates and what its specific rules are. This route has become an important safety net for households who are struggling financially but don’t tick the standard benefits box.
4. Homeowners and Tenants
Both homeowners and tenants can potentially benefit from ECO4, although the process differs slightly:
- Homeowners can apply directly and give consent for the work themselves.
- Private tenants usually need written permission from their landlord before any installation work can go ahead, since the property isn’t theirs.
- Social housing tenants are sometimes covered by separate funding routes, depending on the housing association or council involved, though many will still qualify under ECO4’s general criteria.
If you’re a landlord, it’s also worth knowing that ECO4 can help you meet Minimum Energy Efficiency Standards (MEES) obligations for rental properties, making it a useful funding source even outside of pure tenant welfare considerations.
Read more: Boiler Upgrade Scheme: Grant Amount, Eligibility & Application Process (2026 Guide)What Boilers Are Replaced Under ECO4
ECO4 doesn’t fund boiler replacements indiscriminately. In general, the scheme prioritises:
- Boilers that are broken, unsafe, or beyond economical repair
- Older, inefficient non-condensing boilers being replaced with modern A-rated condensing models
- Homes with no central heating system at all (first-time central heating)
- In some cases, oil or LPG boilers being swapped for more efficient alternatives, including heat pumps
It’s worth noting that ECO4 increasingly favours low-carbon heating solutions such as air source heat pumps over like-for-like gas boiler replacements, in line with the UK’s wider net-zero commitments. If your home is suitable for a heat pump — meaning it has reasonable insulation and space for an outdoor unit — your installer may recommend this instead of, or alongside, a boiler replacement. However, straightforward gas boiler replacements remain widely available under the scheme, particularly for homes not suited to heat pump technology.
How to Apply for an ECO4 Boiler Grant: Step-by-Step
Applying for ECO4 funding is generally free and doesn’t require any specialist knowledge. Here’s how the process typically works.
Step 1: Check Your Eligibility
Start by checking whether you meet the benefits or LA Flex criteria outlined above. Many energy advice websites and installer companies offer free online eligibility checkers that take just a couple of minutes to complete. You’ll usually be asked about:
- Your benefit status
- Your approximate household income
- Your property type and EPC rating (if known)
- Your postcode (to check local authority participation in LA Flex, if relevant)
This step doesn’t commit you to anything — it simply tells you whether it’s worth proceeding further.
Step 2: Contact an Approved Installer or Obligated Supplier
Once you’ve established that you’re likely to qualify, the next step is to get in touch with an ECO4-approved installer or one of the obligated energy suppliers. You do not need to be a customer of a specific energy company to apply — anyone can apply to any participating supplier or installer, regardless of who supplies their gas and electricity.
At this stage, you may be asked to provide:
- Proof of the qualifying benefit (such as a benefits award letter)
- Proof of identity and address
- Details of your current heating system
- Information about your property (age, construction type, number of occupants)
Step 3: Home Assessment
A qualified surveyor will usually visit your property (or in some cases conduct a remote assessment) to evaluate its current energy efficiency, existing heating system, and insulation levels. This assessment determines:
- Your EPC rating, if not already known
- What improvements would most effectively raise your home’s efficiency
- Whether a straightforward boiler swap is appropriate, or whether insulation and other measures should be included
Step 4: Approval and Funding Confirmation
Once the assessment is complete, the installer or supplier will confirm what funding is available and what work will be carried out. In most successful applications, ECO4 covers the full cost of the agreed measures, meaning there’s nothing for the household to pay. In some cases — particularly where a household’s savings only partially meet the funding criteria — you may be asked to make a smaller contribution, though this is far less common for benefit-qualifying households.
Step 5: Installation
All ECO4 installation work must be carried out by a TrustMark-registered business, certified to the relevant industry standard (PAS 2030:2019 for retrofit measures). This certification requirement exists to protect consumers from poor workmanship and rogue traders. A typical straightforward boiler replacement takes one to two days to complete; a heat pump installation may take between two and four days.
Step 6: Certification and Sign-Off
After installation, the work is certified and registered, both to confirm it meets required standards and to allow the installer to claim the funding from the obligated energy supplier. You should receive documentation confirming the work carried out, which is useful to keep for future reference — for example, if you sell your home or need proof of the upgrade for insurance purposes.
How Long Does the Process Take
Timelines vary depending on demand, installer availability, and the complexity of the assessment, but as a rough guide:
- Eligibility checking: a few minutes to a few days
- Home assessment: usually scheduled within one to a few weeks of application
- Approval and funding confirmation: typically a further one to three weeks
- Installation: one to four days on-site, depending on the measure
Overall, most applicants can expect the process from initial enquiry to completed installation to take somewhere between a few weeks and a couple of months, though this can extend during periods of high demand — which is worth bearing in mind given the scheme’s approaching deadline (more on that below).
Read more: Boiler Grants UK: Eligibility, Free Boiler Scheme & How to ApplyImportant: The ECO4 Deadline
ECO4 was originally scheduled to run until March 2026, but it has since been extended through to 31 December 2026. After this date, the scheme in its current form is set to close, and funding is expected to be largely allocated well before the final deadline.
While the government has indicated it will introduce follow-on funding through initiatives connected to the wider Warm Homes Plan, no confirmed successor scheme with matching eligibility criteria has been finalised at the time of writing. Early indications suggest any replacement scheme could focus more heavily on heat pumps and renewable heating rather than like-for-like gas boiler swaps, and may come with different (potentially stricter) eligibility rules.
If you think you might be eligible, it’s sensible not to delay your application. Because installer capacity and remaining ECO4 funding are both finite, applications submitted close to the deadline may not be processed in time for installation to be completed before the scheme closes.
Alternatives if You Don’t Qualify for ECO4
Not everyone will meet ECO4’s criteria, even accounting for LA Flex. If that’s the case for you, there are still other routes worth exploring:
Boiler Upgrade Scheme (BUS)
The Boiler Upgrade Scheme offers grants of up to £7,500 towards the installation of an air source heat pump, or up to £5,000 for a ground source or biomass system. Unlike ECO4, BUS is open to most homeowners in England and Wales regardless of income, provided they’re replacing a fossil-fuel heating system. It doesn’t cover like-for-like gas boiler replacements, but it’s a strong option if you’re open to switching to a heat pump. The scheme is currently set to continue until at least 2028.
Warm Homes: Local Grant
Delivered through local councils, the Warm Homes: Local Grant is aimed at low-income households and is backed by a further £1.5 billion in government funding as part of the broader Warm Homes Plan. Coverage, eligibility, and available measures vary by area, so it’s worth contacting your local council directly to find out what’s on offer where you live.
Energy Supplier Hardship Funds
Many energy suppliers run their own hardship or grant funds for struggling customers, separate from ECO4. These can sometimes help with boiler repairs, energy debt, or emergency heating support, and are worth exploring if you’re a customer of a supplier with such a scheme.
Switching Tariffs
While not a grant, switching to a better energy tariff can meaningfully reduce your bills in the short term while you explore longer-term funding options — sometimes cutting annual costs by 10–20%. This won’t help with the cost of a new boiler, but it can ease pressure on your budget while you wait for a grant application to progress.
Is ECO4 really free, or are there hidden costs?
For most eligible households, the process — from eligibility checking through to installation — comes at no cost. There should be no fee to apply and no obligation to pay anything for a genuine ECO4 assessment. Be cautious of any company asking for upfront payment simply to check your eligibility or book an assessment, as this isn’t standard practice for the scheme.
Will I definitely get a brand-new boiler, or could I be offered insulation instead?
It depends on what your home assessment identifies as the most effective improvement. Some households receive a boiler alongside insulation measures; others may be offered insulation first, with heating upgrades considered separately. The whole-house approach means the specific package is tailored to your property.
Can I apply if I rent my home?
Yes, but private tenants will need landlord permission before installation work can proceed, since the property isn’t owned by the tenant.
What if my EPC rating is already C or above?
ECO4 primarily targets D-to-G rated homes. If your property already has a good EPC rating, you may not qualify for ECO4 specifically, though you could still be eligible for the Boiler Upgrade Scheme if you’re considering a heat pump.
How do I avoid scams?
Only deal with TrustMark-registered installers and be wary of unsolicited cold calls or door-to-door offers pressuring you to sign up immediately. Legitimate ECO4 assessments don’t require you to pay anything upfront, and you should always be given time to consider any offer before agreeing to work being carried out.
What happens after ECO4 ends in December 2026?
While the government has signalled its intention to continue supporting home energy upgrades through the Warm Homes Plan, the exact shape of any successor scheme — including its eligibility rules and whether it will continue funding traditional gas boiler replacements — had not been confirmed at the time of writing. This uncertainty is one reason many advisers are encouraging eligible households to apply now rather than wait.
How many times can I apply for or use ECO4?
There’s generally no fixed limit on how many times a property can receive support under ECO scheme phases over the years, but within a single ECO4 application you’ll typically only go through one full assessment-and-installation cycle. If your circumstances change significantly later on — for example, your EPC rating drops or you start receiving a new qualifying benefit — it’s worth checking with an installer whether further support is available, subject to remaining funding before the scheme closes.
Does ECO4 cover boiler repairs, or only full replacements?
ECO4 is designed around full replacement rather than one-off repairs. If your boiler has a fixable fault, the scheme is unlikely to fund a repair — it’s aimed at swapping out boilers that are broken beyond economical repair, unsafe, or so inefficient that replacement delivers a genuine energy-saving benefit. For minor repairs, you’d typically need to look at your existing boiler warranty, home insurance, or a private repair instead.
Will an ECO4 boiler grant affect my benefits?
No. ECO4 support is a home improvement grant, not income or savings, so receiving it should not affect your entitlement to Universal Credit, Pension Credit, or any other means-tested benefit. It doesn’t count as taxable income either, since no money is paid to you directly.
Can I choose which installer or which boiler brand I get?
You generally can’t hand-pick a specific boiler brand or model, as this is decided by the installer based on what’s appropriate for your property and what’s covered under the funding agreement. You typically can choose which participating installer you apply through, though, so it’s worth comparing a couple of TrustMark-registered installers if you want some say over who carries out the work and how quickly they can start.
Final Thoughts
For households struggling with an old, inefficient boiler and facing rising energy costs, ECO4 remains one of the most valuable support schemes currently available in the UK. It can cover the entire cost of a new, efficient heating system for those who qualify, often alongside insulation improvements that bring lasting reductions in energy bills.
If you receive a qualifying benefit, or you believe you might meet your local council’s LA Flex criteria, it’s worth checking your eligibility without delay — particularly with the scheme’s confirmed end date of 31 December 2026 fast approaching and no guaranteed replacement scheme yet in place. Even if you don’t qualify for ECO4 itself, alternatives like the Boiler Upgrade Scheme or your local Warm Homes: Local Grant may still be able to help.
As with any government-backed scheme, rules, funding levels, and deadlines can change, so it’s always worth confirming the latest details with an official source, your local authority, or a TrustMark-registered installer before making any decisions.
This article is provided for general information purposes only and does not constitute financial or legal advice. Eligibility criteria and scheme details can change, so always verify current requirements with an official installer, your energy supplier, or your local council before applying.