The £7,500 Boiler Upgrade Scheme: full guide for UK homeowners

What BUS is, briefly

The Boiler Upgrade Scheme is a UK government grant administered by Ofgem. It pays £7,500 towards installing an air-source heat pump (or a biomass boiler in rural off-gas areas; or a ground-source heat pump). It applies in England and Wales only. It runs until at least 2028 at current funding levels, with a budget of around £400m/year.

It replaced the older Domestic Renewable Heat Incentive (RHI), which paid quarterly tariffs over seven years. BUS is simpler: one lump sum, deducted from your quote up front. You never handle the money — the installer does.

Who qualifies

• You own a property in England or Wales. Owner-occupiers and private landlords both qualify. New-builds don't (with one obscure exception: self-build properties where you're moving in as your main residence).
• You're replacing a fossil-fuel heating system — gas, oil, LPG, or coal. Direct-electric (storage heaters, electric boilers) currently qualify too, though policy may tighten on this.
• The property has a valid EPC issued in the last 10 years.
• That EPC has no outstanding recommendations for loft insulation (if accessible) or cavity wall insulation (if applicable). If your EPC says "install loft insulation," you have to do it first.
• The installation is done by an MCS-certified installer. Non-MCS installers cannot claim BUS, full stop.

The EPC trap that catches people

This is the single most common reason BUS applications fail or get delayed. The EPC requirements are stricter than most people realise:

1. "Within 10 years" means literally — if your EPC was issued 11 years ago, it's void for BUS even if nothing has changed about your house. New EPC: £60–£120 from a local domestic energy assessor.
2. "No outstanding recommendations" for loft and cavity wall specifically. Other recommendations (LED bulbs, hot water cylinder insulation, etc.) don't block BUS — only those two do.
3. If you've added insulation since the EPC was issued, the EPC won't reflect it. You'll need a new EPC to evidence the upgrade before applying.

Pro move: get a fresh EPC before you start collecting heat pump quotes. It costs the same as a takeaway dinner and removes the single biggest application risk. If the new EPC flags loft or cavity wall, you address those before the heat pump — which is good practice anyway.

What BUS covers — and doesn't

£7,500 is a fixed amount regardless of your total installation cost. It covers the heat pump unit itself and its installation labour. Out of pocket for most homeowners is £2,500–£8,500 after the grant, but the gap exists because of what BUS doesn't cover:

• Radiator upgrades: typically £100–£300 per radiator × 5–15 radiators = £500–£4,500.
• New hot water cylinder: £800–£1,800 for a typical 200-litre unvented cylinder.
• Insulation work: if needed for the EPC or for the system to run efficiently, £500–£6,000 depending on scope.
• Electrical upgrades: if your supply needs reinforcement, £200–£800 for the installer; occasionally more if the DNO triggers a supply change.
• Scaffolding or special access: rare on a heat pump install (no roof work) but occasionally needed for pipe routing in tall buildings.

How the application actually works

You don't apply for BUS yourself. Your installer does, and the process is sequential:

1. Heat loss survey + quote. The installer surveys your home, calculates heat loss room-by-room, designs the system, and produces a quote with the £7,500 BUS already deducted.
2. Pre-application via Ofgem's BUS portal. Your installer submits an application on your behalf — your EPC, the property details, the system spec. You get an email asking you to confirm the application is genuine (you click a link to consent).
3. Provisional approval. Usually within 14 days. The installer can now schedule the installation knowing the grant is reserved.
4. Installation + MCS certification. Done by your installer over typically 3–7 days. The installer issues the MCS commissioning certificate and uploads it to Ofgem.
5. Final payment to installer. Ofgem pays the £7,500 directly to the installer after they receive the commissioning certificate. Usually within 2–4 weeks of completion.

Why applications fail (and how to avoid it)

• EPC issues: by far the most common. Solve by getting a fresh EPC up front (covered above).
• Property type mismatch: the property isn't a primary residence, is on the new-build register, or is classified as a non-domestic dwelling. Check your property's classification before applying.
• Installer not MCS certified at the time of installation — some installers lapse mid-job. Verify the certificate is current on the MCS register before signing.
• System design that wouldn't pass MCS standards: wrong size, missing weather compensation, missing buffer tank where required. This is on the installer, but it can stall your application for weeks.
• Trying to claim BUS twice for the same property within five years. The grant is once-per-property; if a previous owner claimed it, you can't.

Scotland and Northern Ireland: what to look at instead

Scotland — Home Energy Scotland (HES): the Scottish equivalent is more generous than BUS on paper. You can get up to £7,500 as a grant plus up to £7,500 as an interest-free loan (terms vary), giving you up to £15,000 of support — though half of it has to be paid back. Rural properties off the gas grid can get a higher grant. Apply via energysavingtrust.org.uk or call HES directly.

Northern Ireland — Renewable Heat Premium: the NI scheme is administered separately by the Department for the Economy. It's smaller and currently caps support at lower levels than BUS. The mechanism is closer to the old RHI — there's no equivalent up-front grant deduction. Check the latest at NIDirect.

FAQ

Is the £7,500 paid to me or to the installer?

To the installer, not you. Ofgem pays the grant directly to your MCS-certified installer after the installation is commissioned. The installer deducts the £7,500 from your quote up front, so you only pay the net amount. You never see the grant money — it's a price reduction, not a cash payment.

Does the BUS grant cover the whole installation?

No. £7,500 is a fixed grant amount regardless of the total install cost. It covers the heat pump unit itself and its installation labour. It does NOT cover radiator upgrades, new hot water cylinders, insulation work, electrical supply upgrades, or scaffolding.

Do I need an EPC to apply?

Yes — a current EPC dated within the last 10 years, with no outstanding recommendations for loft or cavity wall insulation. Order a fresh EPC before applying if yours is older or absent.

Is BUS available in Scotland or Northern Ireland?

No. BUS applies only in England and Wales. Scotland has Home Energy Scotland (up to £15,000 grant + loan combined). NI has the Renewable Heat Premium.

Can landlords claim BUS?

Yes — both owner-occupiers and private landlords in England and Wales can apply, provided the property is an existing residence (not a new-build) and meets the EPC requirements.

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Related: The full ASHP buyer's guide · Heat pump suitability by house type