# The Boiler Upgrade Rule Opens a Door, Not a Subsidy

Published: 2026-10-28

The UK's 22 October Boiler Upgrade Scheme amendment gives [Keir Starmer](/people/keir-starmer)'s government the legal power to support thermal energy storage — including eligible heat batteries — in a future version of its heating incentive. Households unable to install conventional heat pumps are the clearest prospective beneficiaries, and manufacturers gain a clearer pathway to subsidized demand. The law does not create a heat-battery grant today. Further regulations and product standards are still required. Broadening eligible technologies can make low-carbon heating more practicable in flats and older properties with little outdoor space. If standards are tight and running costs honest, public money can buy real choice; if they are weak, the Exchequer risks funding less efficient options under the same grant frameworks that already strain energy-price politics. A measured energy policy has to keep the gap between enabling legislation and money actually available unmistakable — the same discipline that has already forced Starmer's government to revise green spending promises such as the [GBP 28bn green investment climb-down](/facts/uk-starmer-drops-28bn-green-investment-2024).

## What came into force

Statutory Instrument 2026/1121 was made on 21 October and came into force 22 October ([SI timeline](https://statutoryinstruments.parliament.uk/instrument/DJUW13JL/timeline/FvmUH7G0)). It alters section 100 of the Energy Act 2008 to add qualifying thermal energy storage systems to the category of technologies that can receive support under future renewable-heat schemes. The relevant stored energy must come wholly or partly from renewable sources. The instrument also changes regulation 22 of the 2022 Boiler Upgrade Scheme rules on recovery of inappropriate payments. It allows the scheme administrator, Ofgem, to combine repayment with offsetting against future grant payments, provided that recovery does not exceed what is owed. Both changes passed parliamentary affirmative procedures before the instrument was made ([procedure package](https://api.parliament.uk/procedure-browser/work-packages/FvmUH7G0)). Neither provision authorizes a household to claim a heat-battery subsidy immediately. A future change to scheme eligibility remains necessary. Readers should not confuse a ministerial promise to pursue future support with a completed appropriation, an approved product catalogue or a successful installation.

## The legislative journey

The draft was laid before Parliament in July 2026, debated in the House of Lords Grand Committee in September and the Commons delegated legislation committee in October ([Commons debate](https://hansard.parliament.uk/Commons/2026-10-14/debates/7d2a2129-fa75-4342-9440-d69c4ca1e7ae/DraftBoilerUpgradeScheme%28AmendmentToTheEnergyAct2008Etc%29Regulations2026); [Lords debate](https://hansard.parliament.uk/Lords/2026-09-14/debates/DB087AE7-9E67-45F6-81EE-4016FD8279CF/BoilerUpgradeScheme%28AmendmentToTheEnergyAct2008Etc%29Regulations2026)). Both Houses approved the instrument, with the [House of Commons](/organizations/house-of-commons) completing approval on 19 October. These dated steps matter because secondary legislation can alter the scope of future subsidy powers while remaining too limited to create a new grant. Ministers explained that this was an enabling measure; the government intends another instrument once standards are in place. A parliamentary timeline is useful for checking promises against decisions: the legal basis now exists, but separate standards and funding details remain. Energy Secretary [Ed Miliband](/people/ed-miliband) saying heat batteries are eligible in principle is not equivalent to Ofgem accepting applications. A manufacturer advertising an available government discount without the later rules would risk misleading consumers. The governance test is whether future implementation is clear enough that households and installers can distinguish research, certification and payable grants — a recurring theme across UK government clean-heat delivery and energy security policy.

## What a heat battery does

A heat battery stores thermal energy rather than electricity for later use. Some models use electrically heated storage materials or phase-change systems to deliver hot water or space heating when needed. Such units may lack the outdoor compressor required by a heat pump. This can be advantageous in flats or older properties where external space, planning rules or installation complexity present obstacles. But thermal storage is not a new source of energy; the stored heat must first be produced. A direct electric heater typically turns electricity into heat without the coefficient-of-performance advantage of a heat pump that moves heat from the environment. The economics depend on tariffs, storage losses, operating schedule and the building's heat demand. A battery charged during lower-cost hours could save money compared with using expensive electricity at peak time, yet that is not the same as using less energy overall. Policymakers should compare lifetime cost and emissions, not only the availability of a compact device — especially while households still live inside [cost-of-living pressure](/drivers/econ-cost-of-living-pressure) and volatile bills.

## The causal chain

Parliament expands the Secretary of State's enabling power. Government and certification bodies develop appropriate standards and safeguards. Ministers may then amend the scheme to make specified heat-battery products eligible for support. Installers obtain accreditation and offer compliant designs; households compare heat batteries with heat pumps, insulation upgrades and other heating options. If the grant offsets upfront costs, adoption may rise in properties that otherwise retain gas systems. Actual carbon and bill savings then depend on electricity sources, heat demand, tariffs and equipment performance. The first step has occurred; the subsequent chain is conditional. No number of households benefiting can be inferred from the October instrument alone. Similarly, product manufacturers cannot declare eligibility until standards and regulations establish the criteria. The key measurement is the incremental adoption and cost-effectiveness of useful low-carbon heat, not the number of product types listed in an Act — the same outcome test that should govern [renewable buildout](/drivers/energy-renewable-buildout) more broadly.

## Beneficiary table

| Group | Potential benefit or burden | What we know |
|---|---|---|
| Households unable to install heat pumps | Possible future alternative heating grant | Possible after further rules |
| Heat-battery manufacturers | Route toward certified market and future demand | Pathway opened, not funded |
| Heat-pump installers | Continued existing scheme; possible new competition | Current scheme unchanged |
| Ofgem | Clearer options for recovering erroneous grants | Legal amendment in force |
| Taxpayers | Exposure if future grants are issued inefficiently | Contingent on next SI |
| Energy networks | Potential opportunities for demand shifting | Unproven at scale |
| Parliament | Oversight of technology and spending powers | Affirmative approval recorded |
| Homeowners | More choice only after standards and funding rules | Conditional |

## Why technology-neutral policy matters

The government says heat batteries would complement rather than displace heat pumps, which remain its primary supported technology. That distinction matters because a uniform grant programme can penalize households whose buildings cannot accept the standard option. Flats, listed buildings and houses with restrictive outdoor space may require different solutions. However, technology neutrality cannot mean funding any product that markets itself as low carbon. Policymakers need independent measurements of useful heat delivered, seasonal efficiency, standby loss, safety and installation quality. A direct-electric thermal store might be practical in one home while a heat pump delivers much lower operating energy in another. Consumer choice is genuine only when buyers receive comparable information about upfront cost, expected bills and maintenance. A programme that adds a grant for an unsuitable device can make the household financially worse off despite improving a headline adoption metric. Well-designed eligibility standards protect buyers and the credibility of the clean-heat transition.

## The cost argument from critics

In the September Lords debate, opposition speakers questioned the effectiveness of existing heat-pump subsidies and warned against enlarging spending before proving that the programme delivers affordable heating. They also argued that electricity costs are a major barrier to electrification and that subsidies may redistribute costs unfairly. Those concerns are legitimate questions about policy efficiency, though specific claims about aggregate price causes require separate evidence. The government responded that the Boiler Upgrade Scheme is funded from the Exchequer rather than a direct bill levy, and cited evaluations indicating many recipients reported lower total energy bills. Ministers also reported high levels of recipient satisfaction. These are government-reported outcomes, not randomized proof that every installation saves money. User selection, property condition and the comparison with prior equipment may influence the results. The new heat-battery option should be assessed with the same scrutiny rather than assumed better or worse in advance — especially while Chancellor [Rachel Reeves](/people/rachel-reeves) faces competing fiscal claims on the same public purse.

## Product safety and certification

The government has repeatedly conditioned the future grant on product and installation standards. This is essential because storing substantial heat inside a dwelling requires attention to insulation, fire safety, temperature control and reliable operation. Certification also gives homeowners a way to distinguish independently tested products from prototypes marketed through persuasive advertising. Standards must account for different thermal storage technologies rather than favor one manufacturer without justification. The Microgeneration Certification Scheme has a role in installation certification, but exact future heat-battery specifications should be taken from final rules and published standards. No claim that every existing unit is approved would be defensible today. Regulators also need a route to recall or correct products if safety issues emerge and to ensure warranties are meaningful. A subsidy should not become an incentive to rush untested equipment into homes simply to meet a political deadline. Transparent product information and installer training are prerequisites for effective choice.

## Recovery of public money

The second part of SI 2026/1121 clarifies Ofgem's ability to recover payments that should not have been made to installers. Ofgem may combine repayment demands with offsets against future grants, while the total recovered cannot exceed the amount due. This technical provision is separate from heat-battery eligibility, but it reveals an important governance issue in publicly funded technology markets. Grant systems can suffer from ineligible claims, administrative errors or poor documentation. An administrator needs tools to recover sums promptly and fairly without punishing customers who acted in good faith. A combined recovery power can allow proportionate arrangements where an installer continues participating in the scheme. Yet oversight must prevent arbitrary offsets and ensure there is a route to contest calculations. Financial controls protect the same budget intended to make low-carbon heating affordable. The measure is not proof of widespread fraud; it clarifies recovery mechanics even when an overpayment arose innocently. The [National Audit Office](/organizations/uk-national-audit-office) tradition of tracking whether subsidy programmes deliver value for money remains the right public test once eligibility expands.

## The electricity-system hypothesis

Thermal storage may allow heat production during periods of low electricity demand or abundant renewable generation. If households charge units when wind output is high or tariffs are low, they could reduce demand at expensive peak times. That could help grid management and lower bills under suitable tariffs. But the impact depends on millions of individual decisions and infrastructure capabilities, not simply on a device's presence. Charging all units at the same cheap-price window could create a new peak. Storage losses can also increase total electricity consumption. Network benefits should therefore be assessed with real load profiles and tariff data. Policymakers could test whether devices respond to price signals without harming residents' comfort or ability to control heating. The environmental case is strongest where thermal storage enables otherwise difficult electrification or makes genuine renewable generation more useful. A blanket claim that heat batteries automatically lower grid demand would be misleading.

## Distribution across income and housing types

Homeowners with capital, good credit and suitable properties may capture more grants than renters or households facing repair backlogs. This distributional problem already affects several home-upgrade programmes. A heat battery could broaden access in some compact homes, but the programme should consider who can apply, what upfront payments remain and whether tenants have any say. Landlords may invest only if cost savings benefit them directly, while tenants pay the running bills. Public support should avoid subsidizing wealthy households to replace functioning low-cost systems with equipment that produces limited additional emissions benefits. Means testing or targeted support can improve distribution but also adds administration. Independent analysis should measure take-up by income, dwelling type and region, and examine whether installers serve hard-to-reach households. The policy is not equitable merely because it offers more technology choices; it becomes equitable when choices are realistically available to people facing the greatest heating constraints.

## Procurement and industrial interests

Adding an eligible technology category may stimulate investment in domestic manufacturing, distribution and installer training. Producers have incentives to lobby for standards that match their existing designs, while incumbent heat-pump firms may worry about competition for a finite grant budget. These interests are legitimate but should be visible to regulators. Public eligibility criteria must be grounded in performance rather than political access. Where manufacturers claim local jobs or strategic supply security, evaluators should seek verifiable investment and employment figures. A certification framework that is too expensive could exclude small innovators; one that is too lax could undermine consumer trust. Competitive procurement and transparent testing support a healthy market. It is reasonable for government to facilitate technologies that address difficult building constraints, but public funds should not guarantee commercial success to any particular supplier. The strongest industrial policy creates standards enabling firms to compete on quality, cost and verified energy performance.

## Parliamentary accountability

The instrument used delegated powers to amend part of the 2008 Energy Act after affirmative approval by both Houses ([Joint Committee on Statutory Instruments report](https://publications.parliament.uk/pa/jt5902/jtselect/jtstatin/55/report.html); [Lords Secondary Legislation Scrutiny](https://publications.parliament.uk/pa/ld5902/ldselect/ldsecleg/50/5006.htm)). Such powers are lawful but deserve scrutiny because they can alter the categories that government may subsidize without passing an entirely new primary Act. Committees examined the instrument and did not raise objections requiring special attention. That does not eliminate responsibility to explain future grant details to Parliament. The next statutory step will be more directly relevant to household spending. Ministers should publish why particular products qualify, how much grant support they receive and how the programme interacts with existing heat-pump funding. Public debate should not reduce to a choice between decarbonization and household affordability, because a credible transition must address both. Independent legislative scrutiny is a strength of democratic energy policy: it can catch vague definitions, hidden costs and unsupported performance claims before they affect residents.

## What could happen next

Several paths remain open. Standards could enable a narrow class of safe, practical heat batteries and grants could reach households for whom heat pumps are unsuitable. Certification and further regulations could also take longer than ministers imply, leaving the enabling power unused. High running costs and weak screening could make some subsidized installations less attractive than insulation or a well-specified heat pump. Well-managed units might exploit renewable electricity and time-varying tariffs without creating harmful new peaks — or they might not. None of these outcomes is established by the October instrument. The right evidence will compare whole-life cost and emissions against realistic alternatives in the same homes. Installation numbers alone cannot prove success; a product must also deliver dependable comfort, consumer savings or environmental improvements. Each path needs a different regulatory response, from tighter product guidance to targeted funding or revised standards.

## What to watch

Follow the next statutory instrument that would actually admit heat batteries to the Boiler Upgrade Scheme. Read the final product and installation standards and check independent certification availability. Ask Ofgem for transparent instructions distinguishing supported products from ineligible prototypes. Measure capital cost, seasonal useful heat, electricity tariffs and consumer satisfaction. Examine whether grant amounts encourage overpricing by installers and whether recovery powers are exercised fairly. Compare the distribution of support by income and building type, and ask whether renters are excluded. Monitor grid demand data for any evidence of peak shifting or new pressures. Most importantly, resist the claim that a regulatory amendment has already produced a large number of low-carbon installations. What is proven today is legal permission to design future support; what still has to be shown is whether government implements it with honest standards and measurable value for households and taxpayers.

Britain has changed the legal foundation for heating grants to permit future support for qualifying thermal energy storage, while also strengthening the administration of existing payments. The winners could be households whose homes cannot accommodate standard heat pumps, but the immediate commercial outcome is not a new payable subsidy. Standards and further regulations still separate the political promise from installations. Government and industry should use that interval to establish fair certification, transparent costs and credible performance measures. A democratic clean-heat transition succeeds when households receive safe, affordable options and taxpayers see verified environmental value — a bar SI 2026/1121 sets up but does not yet clear.

## Sources retained from the live page

- [https://factrail.ai/](https://factrail.ai/)

## Methodology

https://factrail.ai/methodology

Canonical: https://factrail.ai/articles/uk-boiler-upgrade-heat-battery-enabling-law-grant-gap-2026