ECO4 and the Great British Insulation Scheme are both government-mandated efficiency schemes, but only ECO4 can ever touch boiler-related work, and even then only in narrow, specific circumstances. GBIS funds insulation only, and if you actually want help with a low-carbon heating upgrade, the separate Boiler Upgrade Scheme is the one to look at instead.

Two different schemes that people often mix up

Government-backed energy efficiency schemes in Great Britain change fairly often – eligibility criteria, funding levels and even which scheme is currently running are periodically updated. The mechanisms described below reflect how these schemes have generally worked; always check GOV.UK or Ofgem directly for the current scheme name, phase and eligibility rules before assuming anything here still applies exactly as written.

ECO (the Energy Company Obligation) and the Great British Insulation Scheme (GBIS) are both government-mandated schemes that require energy suppliers to fund home efficiency improvements, but they cover different things and different households – conflating them is one of the most common sources of confusion, particularly around whether either one will pay for a new boiler.

ECO4: targeted at low-income and vulnerable households

ECO is a long-running obligation placed on larger energy suppliers, requiring them to fund energy efficiency measures for specified groups of households, primarily targeted through two main eligibility routes: households receiving certain means-tested benefits, or households referred through their local authority’s “flexible eligibility” route for people who are low-income or vulnerable but don’t receive a qualifying benefit directly. ECO funding has generally supported a fairly broad range of measures – insulation, heating controls, and in some circumstances central heating or boiler work – but boiler-related support under ECO has typically been tied to a whole-house approach and specific circumstances, such as a broken or condemned heating system, rather than functioning as a general “get a free new boiler” offer for anyone who applies. Don’t assume boiler replacement is automatically included; check what measures you’d actually be assessed for as part of an ECO application.

The Great British Insulation Scheme: insulation only, not boilers

This is the distinction most worth getting right: the Great British Insulation Scheme is specifically an insulation scheme – it does not fund boiler replacement. It’s aimed at a somewhat broader group of households than the benefits-based ECO route, generally combining a property’s Council Tax band and its current EPC rating as eligibility criteria, alongside a separate low-income eligibility route. If you’re specifically looking for help with the cost of a new boiler, GBIS is not the scheme to apply through – it’s worth applying to if loft, cavity wall or similar insulation is what you actually need, but it won’t fund a heating system upgrade.

If you’re actually looking for help with a new heating system

Separately from both of the above, the Boiler Upgrade Scheme (BUS) provides a grant voucher toward the cost of installing a heat pump or, in some circumstances, a biomass boiler, in England and Wales – but it is specifically aimed at low-carbon heating installations, not at replacing an old gas boiler with a new one. If what you actually want is straightforward help with a standard gas boiler replacement, none of ECO4, GBIS or BUS is designed as a general-purpose grant for that – ECO4’s boiler-related support, where it exists, is narrowly targeted through the eligibility routes described above, rather than being available on request.

Scotland and Wales run their own additional schemes

ECO applies across Great Britain, but Scotland and Wales also run their own separate national schemes alongside it – for example, support delivered through Home Energy Scotland in Scotland, and the Welsh Government’s Nest scheme in Wales – with their own eligibility criteria and application routes, distinct from the England-specific detail of some England-only schemes. If you’re in Scotland or Wales, check the relevant national scheme directly rather than assuming an England-focused scheme description applies to you.

How to actually check what you might qualify for

• Use GOV.UK’s or Ofgem’s current eligibility checker rather than relying on older articles or a supplier’s marketing claims;
• Have your Council Tax band, EPC rating and any relevant benefits information ready, since these are common eligibility criteria across these schemes;
• Be cautious of any company cold-calling or door-knocking offering a “free boiler grant” – go through the official GOV.UK or Ofgem routes to check genuine eligibility rather than relying on a salesperson’s claim;
• If you’re in Scotland or Wales, check the national scheme for your nation specifically, alongside GB-wide ECO eligibility.

Watch out for who’s actually delivering the work

Because these schemes are funded through energy suppliers rather than paid directly by government, the actual installation is usually carried out by an approved installer working within the scheme rather than the supplier itself turning up at your door. Genuine scheme installers should be able to confirm which scheme they’re operating under and show relevant accreditation – a legitimate installer won’t be reluctant to explain exactly how the funding works or to put things in writing. If someone’s approach feels rushed, vague about the specific scheme name, or focused on getting a signature quickly rather than properly assessing your home, that’s worth treating as a warning sign regardless of how genuine the underlying government scheme is.

What if you don’t qualify for any of these?

Not qualifying for ECO4 or GBIS doesn’t mean there’s no support available at all – it just means you’re outside the specific eligibility criteria for those particular schemes at this point in time. It’s worth periodically rechecking, since eligibility criteria and scheme phases do change, and worth asking your energy supplier directly whether they offer any additional, supplier-specific support alongside the mandatory schemes, which some do on top of their regulatory obligations.

Frequently asked questions

Will ECO4 or GBIS pay for a new boiler?

GBIS never funds boiler replacement – it’s insulation only. ECO4 can sometimes support boiler-related work, but only tied to a whole-house approach and specific circumstances, such as a broken or condemned heating system, not as a general “free boiler” offer.

What if I want help with a heat pump instead of a new gas boiler?

That’s the Boiler Upgrade Scheme (BUS), not ECO4 or GBIS. BUS provides a grant voucher toward installing a heat pump, or in some circumstances a biomass boiler, in England and Wales.

How do I check what I might actually qualify for?

Use GOV.UK’s or Ofgem’s current eligibility checker rather than an older article or a supplier’s marketing claim, and have your Council Tax band, EPC rating and any relevant benefits information ready.

Sources

• GOV.UK – help with energy bills and home upgrades
• Ofgem – Energy Company Obligation (ECO)
• Ofgem – Great British Insulation Scheme
• Ofgem – Boiler Upgrade Scheme

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