Gas boilers play a huge role in how much it costs to heat your home. Older systems, especially non-condensing boilers, waste large amounts of energy and can be extremely expensive to run. Many homes with outdated heating struggle to stay warm, lose heat quickly, and face rising monthly bills.

Under the ECO4 scheme, you may be eligible for a free boiler replacement if your existing boiler is non-condensing, broken, or not performing efficiently. ECO4 does not replace condensing boilers — only non-condensing boilers are eligible to be swapped.

When approved, your old non-condensing boiler is replaced with a brand-new, A-rated condensing boiler, which is far more efficient and uses much less energy to heat your home. This can significantly lower bills, improve safety, and make your property easier to heat.

Why only non-condensing boilers qualify

The ECO4 scheme is designed to target the homes that need efficiency improvements the most.
Non-condensing boilers:

• Are usually 15+ years old
• Waste heat through the flue
• Cost far more to run
• Have much lower efficiency ratings
• Are more likely to break down

By swapping only non-condensing boilers, ECO4 ensures funding is used where the biggest improvements can be made.

What happens when you qualify?

A qualified surveyor will assess your boiler, check whether it is non-condensing, and determine if a replacement is needed as part of your whole-house plan.

If approved, you will receive:

• A new, energy-efficient condensing boiler
• Updated heating controls
• Safety checks and system tests
• Full installation from a TrustMark-accredited installer

This upgrade helps your home heat up faster, stay warm longer, and use far less gas — reducing both your bills and your carbon footprint.

Who carries out the work?

All installations under ECO4 are completed by fully certified, TrustMark-accredited installers.

Replacing an old, inefficient boiler is one of the quickest ways to improve the comfort and energy performance of your home — and under ECO4, eligible households can receive the upgrade completely free.