Under ECO4, nearly 1 million heating measures have been installed in more than 2,80,000 households by the end of 2025. The scheme is aimed at upgrading poorly performing homes with inefficient and outdated heating systems. The main objective is to reduce fuel poverty in the United Kingdom and provide better living conditions.
According to the new government announcement, the scheme is running until March 2026. The ECO4 Grant provides funding for essential upgrades such as insulation improvements and heating replacements.
In this guide, I will explain how the ECO4 works, who can qualify, and what types of upgrades are covered under the grant.
What Is the ECO4 Boiler Scheme?
The Energy Company Obligation (ECO4) is the fourth and last phase, according to the government’s latest announcement regarding the scheme. This government-backed programme places a legal obligation on large energy suppliers to fund energy-efficiency improvements in eligible homes across the UK.
The scheme focuses on:
- Improving low-efficiency properties
- Reducing household energy bills
- Cutting carbon emissions
- Supporting households vulnerable to fuel poverty
Unlike loans, ECO4 funding is provided as a grant, meaning qualifying households do not need to repay the cost of approved improvements. Low efficiency properties have an EPC rating from Lower D to G.
How Long Will the ECO4 Grant Scheme Run?
The government has announced that the ECO4 Government Scheme will run until March 31st 2026.
As the scheme approaches its final phase, the eligibility criteria and funding availability may become more stringent, making early applications increasingly important. This makes it extremely important to apply without wasting any further time. If you have an old and inefficient boiler, apply for the upgrade today. This will enable you to have an A-rated boiler installed within 4 days.
What Heat Upgrades Are Covered?
The ECO4 funding scheme prioritises whole-house energy performance, targeting measures that deliver long-term efficiency gains rather than short-term fixes.
Common upgrades funded under ECO4 include:
Heating Improvements
Many households can access support for replacing inefficient or non-functional boilers. This support is widely known as the Free Boiler Scheme, Free Boiler Grant, Boiler Replacement Scheme, and also includes heat pumps.
Older boilers, particularly those installed before 2005, are costly to operate and inefficient. Replacing them with modern, A-rated heating systems can significantly reduce heating costs and carbon emissions.
Insulation Measures:
- Internal wall insulation
- External wall insulation
- Loft insulation
- Cavity wall insulation
Insulation plays a key role in reducing heat loss, improving energy performance ratings and is a mandatory part of the government free boiler replacement scheme.
Heating Controls and Efficiency Measures:
ECO4 funding makes it mandatory to cover the following measures, where applicable:
- Smart thermostats
- Improved heating controls
What Is the Free Boiler Scheme?
The government boiler replacement scheme under ECO4 allows eligible households to replace outdated boilers with energy-efficient alternatives at no cost.
This boiler replacement grant is particularly beneficial for homes with:
- D, E, F or G energy performance rating
- High fuel consumption
- Poor heating performance
- Low household income
Condensing boilers operate with over 90% efficiency, reducing energy consumption and low carbon emissions. This helps households cut their energy bills and reduce their negative environmental impact.
Who Is Eligible for the ECO4 Scheme?
Eligibility is based on a combination of household earnings and property energy efficiency.
You may qualify if:
- Your household receives certain income-related benefits, or
- You are referred through ECO4 Flex by your local authority
Which Benefits are Eligible?
If you are on any of the following benefits, you can apply for a free heating system upgrade:
- Universal Credit (UC)
- Housing Benefit
- Pension Credit Guarantee Credit
- Pension Credit Savings Credit
- Income Support (IS)
- Income-based Jobseeker’s Allowance (JSA)
- Income-related Employment and Support Allowance (ESA)
- Working Tax Credit (WTC)
- Child Tax Credit (CTC)
Property requirements typically include:
- A low EPC rating (usually D–G)
- Poor insulation or inefficient heating
- Located in England, Wales or Scotland (not Northern Ireland)
- Owner-occupied or privately rented (with landlord consent)
What Is ECO4 Flex?
ECO4 Flex allows local councils to refer households that may not receive benefits, but:
- Have a low household income (under £31,000)
- Live in energy-inefficient homes
- Are at risk of fuel poverty
- Have a particular health condition
This flexible route has widened access to ECO4 funding, including eligibility for free boiler grants and insulation improvements, without the qualified benefits.
How Much Does the ECO4 Funding Cover?
In many cases, ECO4 funding covers:
- Heating unit costs
- Installation
- Labour and materials
There is no cash payment to the household, but they get an upgraded energy-efficient heating system without paying a single penny. Instead, funding is paid directly to accredited installers carrying out the work.
How the ECO4 Application Process Works
While the process can vary slightly, it typically includes:
- Eligibility assessment
- Property survey by a qualified assessor
- Grant approval
- Installation by an approved installer
- Post-installation quality checks
Installations are completed within days, depending on the measure being installed.
ECO4 Funding Scheme vs Other Energy Grants
Compared to other UK energy initiatives, this specific scheme is:
- Income-focused
- Designed for inefficient homes
- Inclusive of heating and insulation measures
- Come at no cost to the recipient
This makes it particularly suitable for households seeking support through a boiler replacement scheme rather than newer low-carbon technologies that may require upfront costs.
Properties after completed installation measures move up from EPC ratings of D-G to C or D.
Why the ECO4 Scheme Matters in 2026
With energy prices remaining volatile and housing efficiency standards tightening, the ECO4 government scheme, impending the end date, continues to play a vital role in:
- Reducing household energy costs
- Supporting a vulnerable resident
- Improving the UK’s housing stock
As the scheme nears its conclusion, households considering a free boiler grant or insulation upgrade may benefit from acting sooner rather than later. Apply today, as the applications are closing soon for the fourth and final phase of ECO.
Final Thoughts
The ECO4 Government Scheme provides eligible UK households with a practical pathway to improving energy efficiency. It helps in cutting energy costs and reducing environmental impact by installing eco-friendly measures. Through measures such as insulation upgrades, free air source heat pump, solar panels and the free boiler scheme, ECO4 remains one of the most accessible energy-efficiency programmes available in the UK today.