Boiler Upgrade Scheme law changed for heat batteries: what it means

You cannot get a Boiler Upgrade Scheme (BUS) grant for a heat battery today. A change to the law has made it possible for that to happen later, but the money and the rules are not in place. If you are planning a heating upgrade now, nothing in this news changes your options or your costs.

What happened

According to Impakter, the government has amended the Energy Act 2008 so that thermal energy storage systems can be supported by renewable-heat schemes such as BUS. The Boiler Upgrade Scheme (Amendment to the Energy Act 2008 etc.) Regulations 2026 came into force on 22 October 2026. The change applies only where the stored energy comes wholly or partly from renewable sources.

Heat batteries are one type of these systems. Impakter reports that the Department for Energy Security and Net Zero describes them as units that can charge from the grid when power is plentiful and renewable, then release heat when electricity is more carbon-intensive.

The same regulations also change how Ofgem handles installers who are paid a grant they should not have received. According to Impakter, Ofgem can now ask for the money back, deduct it from future grant payments, or do both, as long as it does not recover more than is owed.

What has not changed

Impakter is clear that this is groundwork rather than a new grant:

• GOV.UK guidance still lists grants for air source and ground source heat pumps, biomass boilers and air-to-air heat pumps. Heat batteries are not on that list.
• The government has said it intends to support heat batteries through BUS with an initial grant of £2,500, but only once suitable product and installation standards exist.
• Further changes to the BUS regulations would be needed before any household could claim.

There is no start date in the source, so we are not guessing one.

What it means for your costs

We do not price heat batteries, because there is no grant, no settled standard and no reliable installer market to base a figure on. Here is how we would approach the projects that are priced.

Air source heat pumps. The existing grant is unchanged: £7,500 off an air source or ground source heat pump in England and Wales, provided the installer is MCS certified. In Scotland, Home Energy Scotland offers a grant of up to £7,500 plus an optional £7,500 interest-free loan. Our mid-range heat pump installation is typically £12,900, with a usual range of £10,100 – £16,800, before any grant. See our [heat pump cost guide](Air source heat pump) for how we build that figure from labour hours, local rates and materials.

Boiler replacement. If you are weighing a new gas boiler against a heat pump, a mid-range boiler is typically £2,800. Our [boiler cost guide](New boiler) breaks down the options. A boiler has no grant attached, so the comparison depends on the £7,500 off a heat pump and on running costs.

Should you wait for heat batteries? We would not. A grant of £2,500 is a stated intention, not a commitment with a date, and it would be well below the support available for heat pumps today. Waiting could mean paying more to keep an ageing boiler going.

Deadlines that do matter

One date is firm. Installing energy-saving materials, including heat pumps, insulation, solar panels and batteries, is charged at 0% VAT until 31 March 2027. Our figures include 20% VAT except where 0% applies, so quotes for this work should reflect the lower rate while it lasts. The Warm Homes Plan, published in January 2026, also commits £15bn to 2030, including grants for low-income households and low- or zero-interest loans that are being phased in.

Before you sign anything

• Check that any heat pump installer is MCS certified. Without that, you cannot claim the BUS grant.
• Ask for the grant to be shown as a separate line deducted from the price.
• Be sceptical of anyone selling a heat battery "with a government grant". As things stand, none exists.
• Gas work, such as disconnecting an old boiler, must be done by a Gas Safe registered engineer.

If you already have a quote, use our "is my quote fair" tool to compare it with the live cost model. We will update this piece if the government publishes standards or opens a heat battery grant.