The Boiler Upgrade Scheme, explained properly
Last verified: 28 July 2026 — checked line by line against Ofgem and GOV.UK.
What counts as the system you are replacing
GOV.UK describes the scheme as replacing fossil fuel heating systems — and is explicit that this includes oil, gas, electric and LPG. It works for a home or a building used for your business.
What it will not do: you cannot use the grant to replace an existing low carbon heating system. If you already have a heat pump, this is not a route to a newer one.
The capacity limits
These are the ceilings GOV.UK publishes. Most domestic installations sit well under the first one, but they matter for larger properties:
- 45kWth for individual systems
- 70kWth where a heat pump is installed with one or more additional heat pumps
- 300kWth for shared ground loops
The system must also meet minimum efficiency standards. Your installer is the one who confirms a specific model qualifies — that is part of what MCS certification is for.
Three things that disqualify people
- Hybrids. A gas boiler combined with an air source heat pump does not qualify. GOV.UK says this outright.
- A second grant on the same property. It is one grant per property.
- Going it alone. There is no self-application route. If an installer is not MCS certified, there is no voucher.
Eligibility: only two conditions
GOV.UK’s eligibility page is shorter than most people expect. You qualify if both of these are true:
- you own the property — including a business, a second home, or one you rent to tenants
- you are replacing a fossil fuel heating system — oil, gas, electric or LPG
There is no EPC requirement. Older guidance told people to sort out loft and cavity wall insulation before they could qualify; that is out of date. GOV.UK now states the opposite of the common assumption: “You’re still eligible if you’ve already had funding to make your property more energy efficient, for example by insulating it.”
Electric heating counts as a system you can replace. A lot of guidance says “oil or gas” and stops there, which wrongly rules out electrically heated homes.
One deadline that catches people: “Your installer must commission and install the heat pump within 120 days of applying for the grant or it will not be eligible.”
Properties that cannot get a grant: most new builds, social housing, and any property already given government funding or support for a heat pump or biomass boiler. Self builds qualify if you or the original owner built it and it has never been owned by a business.
Who does what
Ofgem administers the scheme — it processes voucher applications and payments, publishes the guidance and monitors compliance. The Department for Energy Security and Net Zero (DESNZ) owns the policy and legislation. If a figure on this page ever disagrees with Ofgem, Ofgem is right and we are out of date — tell us.
Sources
- Ofgem — Boiler Upgrade Scheme (BUS): grant values including the £9,000 off-gas-grid uplift, scheme roles, installer-led process.
- GOV.UK — Apply for the Boiler Upgrade Scheme: which fuels count, coverage in England and Wales.
- GOV.UK — What you can get: capacity limits, hybrid exclusion, one grant per property.
- GOV.UK — Check if you’re eligible: the two eligibility conditions, absence of any EPC requirement, prior-funding rule, 120-day install deadline, excluded property types. Page updated 28 April 2026.
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