Boilers Fitted Under the ECO4 Scheme
The Energy Company Obligation 4 (ECO4) scheme is a government-backed initiative in the UK designed to improve energy efficiency in homes, particularly for low-income and vulnerable households. Running until March 2026, ECO4 focuses on reducing fuel poverty and cutting carbon emissions by upgrading heating systems and insulation in homes with poor energy performance.
One of the central elements of the ECO4 scheme is the replacement of outdated or inefficient boilers. Let’s explore the types of boilers typically fitted under this programme and how they contribute to more efficient, cost-effective heating.
Types of Boilers Installed Under ECO4
What Are the Grant Schemes?
Combi boilers are one of the most popular options installed through ECO4 due to their compact design and efficiency. They combine a water heater and central heating system in one unit, eliminating the need for separate water tanks.
Key Benefits:
- Instant hot water on demand
- Space-saving design ideal for smaller homes
- High energy efficiency ratings
- Reduced installation complexity and cost
All new boiler installations under ECO4 are required to be condensing boilers. These units are designed to recover heat from exhaust gases that would otherwise be wasted, making them more efficient than older models.
Key Benefits:
Over 90% efficiency in many cases
Lower energy bills
Reduced carbon emissions
Compatible with both gas and oil heating systems
System boilers are suitable for homes with higher hot water demands. Unlike combi boilers, they work with a hot water storage cylinder but do not require a cold water tank. These are often installed in larger properties under the scheme.
Key Benefits:
Consistent hot water to multiple taps simultaneously
Ideal for homes with multiple bathrooms
Faster hot water
- recovery times compared to regular boilers
Also known as heat-only boilers, these are suited for homes with existing traditional heating systems. They work with a hot water cylinder and cold-water storage tanks and are commonly replaced under ECO4 where a like-for-like replacement is most practical.
Key Benefits:
- Good for older properties with existing pipework
- Can support large volumes of hot water
- Ideal where the infrastructure is already in place
Back boilers, often found behind fireplaces in older homes, are highly inefficient by modern standards. ECO4 offers full replacements for these systems, typically upgrading them to combi or system boilers depending on the home’s needs.
Key Benefits:
Major improvement in energy efficiency
Enhanced home safety and reliability
Opens up additional space within the property
Boiler Type Comparison Table
| Boiler Type | Space Needed | Hot Water Availability | Efficiency | Best For |
|---|---|---|---|---|
| Combi | Low | Instant, on demand | High | Flats, small to medium homes |
| Condensing | Medium | Varies (based on boiler type) | Very High | All property types |
| System | Medium | Stored, consistent supply | High | Medium to large homes |
| Regular (Conventional) | High | Stored, good for high demand | Moderate | Large or older homes |
| Back Boiler Upgrade | Varies | Upgraded to modern type | High | Homes with legacy systems |
Why Replace Old Boilers?
Many homes in the UK still rely on boilers installed over 10–20 years ago. These older systems:
Waste a significant amount of energy through exhaust gases
Often require frequent repairs
Contribute to higher heating costs and CO₂ emissions
Struggle to keep up with modern heating and hot water demands
Installing a modern A-rated boiler through ECO4 can reduce household energy bills by hundreds of pounds each year, especially when combined with insulation upgrades and smart heating controls.
Who Qualifies for a Boiler Under ECO4?
Eligibility is based on a combination of household income, benefits received, and the energy performance of the property. Typically, applicants must:
Own or privately rent a home with an EPC rating of D or lower
Have an inefficient existing heating system
Be in receipt of qualifying benefits (such as Universal Credit, Pension Credit, or similar)
Live in a property where improvements will have a measurable impact on energy efficiency
Assessments are carried out by approved retrofit coordinators who determine the most appropriate upgrades based on the specific property.
Modern Features Included with ECO4 Boilers
Many boilers fitted under the scheme now come with smart or programmable controls as standard. These devices:
Improve user control over heating
Automatically adjust heating output based on usage patterns
Can be managed remotely via apps
Enhance overall energy savings by reducing unnecessary heating
Some installations may also include thermostatic radiator valves and advanced weather compensation controls to further optimise performance.
Installation Process
Eligibility Assessment – A provider assesses your home and current heating system.
Energy Survey – A qualified surveyor determines the most effective upgrade for your property.
Installation – A certified engineer removes the old boiler and fits the new, more efficient model.
Post-Install Checks – System testing, efficiency verification, and instruction on how to use your new boiler.
Benefits of ECO4 Boiler Installation
Zero Cost (for eligible households) – Fully funded with no hidden charges
Energy Savings – Dramatically lower heating bills
Home Comfort – Faster heat-up times, even warmth across rooms
Eco-Friendly – Reduced carbon footprint and fuel usage
Increased Property Value – Energy-efficient homes are more attractive to buyers and renters
Summary
The ECO4 scheme plays a vital role in modernising the UK’s domestic heating infrastructure. By fitting efficient boilers whether combi, system, condensing, or replacing outdated back boilers, the programme helps households stay warm, save money, and reduce environmental impact.
If you believe you may be eligible, it’s worth exploring the options available through a registered ECO4 provider. A new boiler could be a major step toward a warmer, more affordable, and sustainable home.
