Boiler Upgrade Scheme 2026: How to Get £7,500 (Step by Step)

Boiler Upgrade Scheme 2026: Complete Application Guide

The Boiler Upgrade Scheme (BUS) is the UK government's flagship grant for replacing fossil fuel heating systems with low-carbon alternatives. It currently offers £7,500 towards the cost of an air source heat pump or ground source heat pump, and up to £7,500 for biomass boilers in rural properties not connected to the gas grid.

The scheme is administered by Ofgem on behalf of the Department for Energy Security and Net Zero (DESNZ). It covers England and Wales only (Scotland and Wales have their own additional schemes — see the Home Energy Scotland and Nest programmes for parallel support). Budget for 2025/26 is £295 million. Money is available — do not delay your application on the assumption that funds will run out.

Important: You never receive the £7,500 in cash. Your MCS-certified installer applies for the voucher and deducts the grant value from your final invoice. Your only job is to ensure your property is eligible and to choose a qualified installer.

What the Boiler Upgrade Scheme Covers

Technology	Grant Amount	Notes
Air Source Heat Pump (ASHP)	£7,500	The most commonly installed technology under BUS
Ground Source Heat Pump (GSHP)	£7,500	Includes water source heat pumps
Biomass Boiler	£7,500	Rural properties only, not connected to the gas grid, with limited exceptions

The grant was increased from £5,000 (ASHP) and £6,000 (GSHP) to £7,500 for both in October 2023 and has remained at that level for 2025/26. The biomass boiler grant was added to support rural households without access to mains gas.

The scheme does not cover hybrid systems (a combination of gas boiler and heat pump), solar panels, battery storage, or district heating connections. For solar panels, see our solar panel costs guide — these carry 0% VAT instead of a direct grant.

Eligibility: Who Qualifies?

The Boiler Upgrade Scheme has a relatively short eligibility checklist compared to means-tested schemes like ECO4. You do not need to be on a low income to qualify — it is open to all owner-occupiers in England and Wales, and to some landlords.

Property Requirements

Location: The property must be in England or Wales. Scotland has its own schemes — see the Home Energy Scotland grant guide.
Valid EPC: The property must have a current Energy Performance Certificate (EPC) issued within the last 10 years. The EPC must not have any outstanding recommendations for loft insulation or cavity wall insulation — if it does, those measures must be completed first, or you must obtain a new EPC showing they are not applicable (for example, if your walls are solid and cavity fill is not possible).
Existing fossil fuel system: You must be replacing a fossil fuel heating system — gas, oil, LPG, or direct electric heating. You cannot use BUS to replace an existing heat pump.
Property type: Houses, bungalows, and self-contained flats all qualify. New-build properties and new-build conversions where planning consent was granted within the past two years are excluded.

The EPC Loft and Cavity Wall Rule — Explained

This is the most common reason applications are delayed or rejected. Your EPC assessor will have noted any "easily installed" insulation that is missing. If your EPC lists loft insulation or cavity wall insulation as a recommended improvement, you must either:

Install those measures before applying (the new EPC will then not list them as recommendations), or
Obtain a statement from a qualified surveyor confirming the measures are not technically feasible or appropriate for your property (for example, your loft is already fully insulated, or your cavity walls are unsuitable for injection due to their condition or exposure).

If your property has solid walls (common in homes built before 1920), the EPC should not flag cavity wall insulation as a recommendation. Your installer can advise — this is a common scenario in older housing stock and is well understood.

Who Applies?

Your MCS-certified installer applies for the voucher on your behalf through the Ofgem portal. You do not apply directly. However, you do need to confirm eligibility and ensure the EPC is in order before your installer submits the application.

The Application Process: Step by Step

Below is the full process from start to finish. Most households complete steps 1 to 6 within 6 to 12 weeks, though timescales vary based on installer availability.

Step 1: Obtain or Renew Your EPC

Check whether your property has a valid EPC at gov.uk/find-energy-certificate. If your certificate is older than 10 years, or if your property has never had one, you will need a new assessment.

An EPC costs around £60–£120 from an accredited assessor (find one at the Landmark register or through the Energy Saving Trust). The assessment takes around an hour and covers the building fabric, heating system, glazing, and insulation.

If your EPC lists loft insulation or cavity wall insulation as a recommendation and you have not had those measures installed, address them now — before proceeding. In many cases you may qualify for free installation through the Great British Insulation Scheme or ECO4. Check eligibility before spending anything.

Step 2: Get Quotes from MCS-Certified Installers

Only installers who hold MCS (Microgeneration Certification Scheme) certification for heat pumps can apply for the Boiler Upgrade Scheme on your behalf. Using a non-MCS installer means you will not receive the grant — there are no exceptions.

Check any installer's MCS certification at mcsregistered.com before agreeing to any work. We strongly recommend getting at least three quotes. Heat pump installation prices vary considerably between installers, and a difference of £2,000–£4,000 between quotes for the same property and specification is not unusual.

When requesting quotes, ask each installer:

What size heat pump they are specifying and why (ask to see the heat loss calculation — this should be carried out to MIS 3005 standard)
Whether any changes to radiators or distribution pipework are included
What hot water cylinder is included (if applicable)
Whether they will handle the BUS voucher application and EPC check
Their expected lead time from deposit to installation

Step 3: Your Installer Applies for the Voucher via Ofgem

Once you have agreed terms with your chosen installer, they apply for a BUS voucher through the Ofgem portal. They will need:

Your property's EPC reference number
Confirmation that no outstanding loft or cavity wall insulation recommendations exist
Details of the heat pump model being installed
Their MCS installer reference number

Ofgem typically processes voucher applications within 5–10 working days. You will receive a confirmation email when the voucher is issued.

Step 4: Voucher Issued — Valid for Three Months

The BUS voucher is valid for three months from the date of issue. The installation must be completed and the voucher redeemed within this window. If circumstances change — for example, if you need to delay due to building work — your installer can apply for a reissue, but this is not guaranteed. It is in everyone's interest to proceed promptly once the voucher is issued.

Do not let your installer begin ordering equipment or starting work before the voucher is issued. The grant cannot be applied retrospectively to work that has already begun.

Step 5: Installation

The heat pump installation itself typically takes 2–4 days for an air source system. This covers removing the old boiler or heating system, installing the outdoor unit (the compressor), fitting or connecting the hot water cylinder, and commissioning the system.

Your installer should carry out a thorough commissioning process, including setting the flow temperature correctly (typically 45–55°C for a heat pump — much lower than a gas boiler), balancing the radiator circuit, and demonstrating how to use the controls. MCS requires evidence of commissioning to be recorded.

Step 6: MCS Certificate Issued and Voucher Redeemed

After installation, your installer generates an MCS installation certificate through the MCS database. This certificate is the proof that the work was completed to the required standard. It is also required to register for certain time-of-use electricity tariffs designed for heat pump owners (such as Octopus Cosy or Economy 7 equivalents).

The installer then redeems the voucher with Ofgem, and Ofgem pays the installer directly. The £7,500 grant is deducted from your final invoice — you pay only the balance. Keep a copy of your MCS certificate and the installer's invoice showing the grant deduction.

Budget and Availability: Is the Money Running Out?

The Boiler Upgrade Scheme has an annual budget set by the Treasury. The 2025/26 budget is £295 million. For context, around 35,000–40,000 heat pumps are being installed under the scheme per year at the current rate — well within the budget's capacity.

Ofgem publishes a monthly dashboard showing vouchers issued against budget. As of early 2026, uptake has not come close to exhausting the available budget in any quarter. The scheme is confirmed to run until at least March 2028 under current government commitments, and the Heat and Buildings Strategy indicates support will continue beyond that date.

The risk of the scheme changing is real — grant amounts have changed before — but the risk that the money runs out before you can apply is low. That said, installer availability is a genuine constraint: the best MCS-certified installers in many areas have waiting lists of 4–8 weeks, so beginning the process sooner rather than later is sensible.

Common Rejection Reasons

Ofgem rejects a small but meaningful proportion of BUS applications. The most common reasons are:

EPC loft or cavity wall issue: The EPC has an outstanding recommendation for loft or cavity wall insulation that has not been addressed or ruled out. This is by far the most common reason for rejection — check your EPC carefully before proceeding.
No valid EPC: The EPC has expired (older than 10 years) or was not obtained for the property before the application.
New-build property: Properties where planning permission was granted within the previous two years are ineligible.
Replacing an existing heat pump: The scheme is for fossil fuel replacement only.
Work started before voucher issued: The grant cannot be applied to installations where work began before the voucher was granted.
Non-MCS installer: The installer is not currently MCS certified for the technology type installed.
Incorrect property address or EPC reference: Administrative errors — these are usually fixable but cause delays.

If your application is rejected, Ofgem will give a reason. In most cases the issue is correctable — for example, getting the outstanding insulation installed and a new EPC issued before reapplying.

Typical Timeline from Decision to Installation

Stage	Typical Duration	Notes
Obtain or renew EPC	1–2 weeks	Allow more time if outstanding insulation measures are needed
Get 3 installer quotes	2–4 weeks	MCS installers can be busy — start early
Choose installer and agree contract	1 week	Confirm they will handle BUS application
Installer submits BUS application to Ofgem	5–10 working days	Voucher emailed when approved
Wait for installation slot	2–6 weeks	Voucher must be redeemed within 3 months
Installation and commissioning	2–4 days	Typically completed in a single visit
MCS certificate and voucher redemption	1–2 weeks post-install	Ofgem pays installer; you pay installer the balance

Total typical timeline: 6–12 weeks from decision to a working heat pump. At the busy end of the season (autumn) this may extend to 14–16 weeks due to installer demand.

How the Grant Payment Works

A common source of confusion is how the money actually flows. To be clear:

You do not receive £7,500 in your bank account.
Your installer deducts £7,500 from your invoice before presenting it to you.
You pay the installer only the balance (installation cost minus £7,500).
Ofgem then reimburses the installer for the £7,500 directly.

For example, if your installer quotes £11,000 for a full air source heat pump installation, your invoice after the BUS grant will be £3,500. You pay £3,500. The installer claims £7,500 from Ofgem.

This structure means there is no cash advance required from you, no grant application form for you to complete personally, and no waiting for a rebate after the fact. The grant simply reduces what you owe your installer.

Combining BUS with Other Grants and Schemes

The Boiler Upgrade Scheme can be combined with several other forms of support:

ECO4 and Great British Insulation Scheme

If your property qualifies for ECO4 or the Great British Insulation Scheme, you may be able to get insulation measures installed for free — which will then clear any EPC recommendations and make your property BUS-eligible. Completing the insulation first, then applying for BUS, is a very efficient sequence for eligible households.

Home Upgrade Grant (HUG2) — England

The Home Upgrade Grant (administered by local councils) provides funding for low-income households in properties not connected to the gas grid. HUG2 can cover insulation and heat pump installation together. Check with your local council or the Energy Saving Trust to establish whether BUS or HUG2 is more advantageous for your specific situation — in some cases HUG2 covers more of the cost for eligible households.

Home Energy Scotland (Scotland Only)

Scotland is not covered by BUS, but Home Energy Scotland offers interest-free loans of up to £15,000 for heat pump installation, alongside separate cashback grants. Scottish homeowners should use this scheme rather than BUS.

Welsh Government Warm Homes Programme

Wales participates in BUS, but also has its own Warm Homes Nest and Optimised Retrofit Programme for eligible households. Welsh homeowners may be able to combine BUS with Welsh Government support for insulation measures.

Smart Export Guarantee (SEG)

If you install solar panels at the same time as your heat pump (or subsequently), you can register for the Smart Export Guarantee and receive payment for excess electricity exported to the grid. BUS and SEG are fully compatible — many households pair a heat pump with solar panels to maximise self-consumption and minimise running costs. See our solar panel costs guide for details.

0% VAT on Heat Pumps

Heat pump installations are subject to 0% VAT (reduced from 5% in 2022, then to 0% from February 2024). This saving is already factored into installer quotes — you do not need to do anything separately to claim it.

Frequently Asked Questions

Can landlords apply?

Yes. Landlords who own residential properties in England and Wales can apply for BUS through an MCS installer. The same eligibility requirements apply. The tenant must be consulted and agree to the installation. Note that ECO4 has different, often more generous, provision for rental properties — check both schemes.

Can I use BUS for a new build?

No. Properties where planning permission was granted within the two years prior to the application date are excluded. New builds are expected to meet Future Homes Standard requirements and should not require the grant incentive.

What if I get more than one quote and they specify different heat pump sizes?

This is common and is worth investigating. A correctly specified heat pump must be sized from a heat loss calculation (MIS 3005). An undersized heat pump will struggle in cold weather; an oversized one will short-cycle and waste energy. Ask each installer for their heat loss calculation and the basis for their specified output. The cheapest quote is not always the best — an installer who has undersized the unit to win on price will cost you more in the long run.

Is the scheme means-tested?

No. Unlike ECO4 and GBIS, the Boiler Upgrade Scheme is not means-tested. It is available to all owner-occupiers and landlords in England and Wales regardless of income, as long as the property meets the eligibility criteria.

My installer wants a deposit — is that normal?

Yes. Most heat pump installers require a deposit (typically 10–25% of the total cost) to secure the installation date and order equipment. Ensure your contract is clear about what happens to your deposit if the BUS voucher application is rejected. Pay by credit card where possible for additional consumer protection.

Next Steps

To move forward with a Boiler Upgrade Scheme application:

Check your current EPC at gov.uk/find-energy-certificate
If your EPC flags loft or cavity wall insulation, check whether you qualify for free installation via ECO4 or GBIS first
Get quotes from at least three MCS-certified installers (check mcsregistered.com)
Ask each installer to provide a heat loss calculation and a detailed specification
Confirm your chosen installer will handle the Ofgem voucher application
Use our heat pump savings calculator to model your expected running costs and savings

For the full context on heat pump installation — costs, what to expect, and how to choose a system — see our air source heat pump costs guide and our complete home energy efficiency guide.