Boiler Upgrade Scheme 2026: Complete Application Guide

It's not means-tested. You don't need to be on benefits. You just need to own a property in England or Wales and be replacing a fossil fuel heating system. The whole process takes 6–12 weeks. The budget isn't running out. The main bottleneck is finding a good installer, not the money.

What's changed, on DESNZ's own list: 8 May 2024, the requirement to clear outstanding loft and cavity wall insulation recommendations on your EPC was removed. 28 April 2026, the requirement for a valid EPC was relaxed, air-to-air heat pumps were added at £2,500, and installers were required to deduct the grant from your upfront cost. 21 July 2026, the £9,000 grant opened for off-gas-grid homes heated by oil or LPG.

BUS by the Numbers

The scheme opened to voucher applications in May 2022. These are the latest official DESNZ statistics, covering everything up to the end of July 2026 (published 27 August 2026):

July 2026 was the busiest month the scheme has ever had: 8,150 applications, 81% up on June and 112% up on the same month a year earlier. The £9,000 off-grid grant is clearly doing some of that work, with 3,037 applications for it in its first ten days. Of the 90,115 installations paid for so far, 56% replaced gas, 17% oil and 13% went into homes that had no heating system at all. Uptake is growing fast, but it still isn't close to exhausting the budget.

What the Scheme Covers

The ASHP and GSHP grants were increased from £5,000 and £6,000 respectively to £7,500 on 23 October 2023. Air-to-air heat pumps were added on 28 April 2026. They're cheaper to install (around £4,500 typically) but don't heat water, so they're best suited to well-insulated properties with an existing immersion heater or separate water heating.

DESNZ's published objectives for the scheme mention heat batteries alongside heat pumps, but there is no heat battery grant live today and Ofgem doesn't list one, so don't plan around a figure for it. The scheme also does not cover hybrid systems (gas boiler plus heat pump), solar panels, battery storage, or district heating, and you can't use it to replace an existing low carbon heating system. There are capacity limits too: 45kWth for a single system, 70kWth where heat pumps are combined, 300kWth for shared ground loops. For solar, see our solar panel costs guide. Solar carries a VAT break rather than a direct grant, and that break runs out on 31 March 2027.

Check If You Qualify

Use our eligibility checker to see which grants you might qualify for. It covers BUS plus five other UK energy schemes:

Eligibility: The Full Details

BUS has a much shorter eligibility checklist than means-tested schemes like ECO4. Here's what you need:

You Must

• Own the property, including second homes, buy-to-lets, and small business premises
• Be in England or Wales. Scotland has the Home Energy Scotland Grant and Loan instead (£7,500 grant, rising to £9,000 with the rural and island uplift, plus an optional interest-free loan of up to £7,500). Northern Ireland has no BUS equivalent, and its Boiler Replacement Scheme has closed.
• Be replacing fossil fuel heating: gas, oil, LPG, or electric storage/panel heaters all count. You can't use BUS to replace an existing heat pump.
• That's it. You do not need an EPC. DESNZ relaxed the valid-EPC requirement on 28 April 2026, and gov.uk's eligibility page no longer mentions an EPC at all. It says in as many words that you're still eligible if you've already had funding to make your property more energy efficient, for example by insulating it.

You Can't Apply If

• Your property is a new build (most are excluded; see the FAQ below for exceptions)
• It's social housing
• You've already received government funding for a heat pump or biomass boiler at this property

Insulation Requirements: The Rule That No Longer Exists

Before May 2024, your EPC couldn't have outstanding recommendations for loft or cavity wall insulation, which blocked thousands of applications. DESNZ removed that requirement on 8 May 2024. You no longer need to address insulation recommendations before applying, and since 28 April 2026 you don't need a valid EPC at all.

That said, insulation still matters practically. A heat pump works most efficiently in a well-insulated home, and you'll pay less to run it. If the loft is bare or the cavities are empty, fix that first, especially if you'd qualify for free insulation through ECO4 (Great Britain, running until 31 December 2026) or the Warm Homes: Local Grant (England). It's just no longer a BUS eligibility requirement. The Great British Insulation Scheme closed on 31 March 2026, so anyone offering you "GBIS funding" is either confused or not to be trusted.

Biomass Boiler: Extra Requirements

Biomass boilers have tighter rules than heat pumps. You must be off the gas grid, in a rural location, and the boiler must have an emissions certificate. Self-build properties aren't eligible for biomass. Most people applying under BUS are going for heat pumps; biomass is the niche exception.

What You'll Actually Pay

Everyone wants to know the bottom line. Here's what a typical air source heat pump installation costs before and after the grant:

Want a more detailed estimate? Use our calculator. Pick your technology, home size, and any extras to see a personalised ballpark:

Three Real Cost Examples

These are representative scenarios based on typical 2025/26 installer quotes:

The 2-bed terrace scenario isn't unusual: for smaller properties with straightforward installations, the £7,500 grant can genuinely cover the entire cost. That's why the scheme exists.

The Application Process: Step by Step

Here's the full journey from start to finish. Most households complete it in 6–12 weeks.

How the Grant Payment Works

This confuses a lot of people, so let's be completely clear:

• You do not receive £7,500 in your bank account
• Your installer deducts the grant from your invoice before presenting it to you
• You pay the installer only the balance
• Ofgem reimburses the installer directly

Example: installer quotes £11,000. Your invoice shows £11,000 minus £7,500 BUS grant = £3,500 to pay. You pay £3,500. Ofgem sends £7,500 to the installer. No cash advance from you, no rebate to wait for, no forms for you to fill in.

Common Rejection Reasons (and How to Avoid Them)

Ofgem rejects a small but real proportion of applications. Here's what goes wrong and how to prevent it:

If rejected, Ofgem explains why. Most issues are correctable: fix the error and your installer can reapply. You won't be asked for an EPC, so don't let anyone tell you to go and buy one.

Budget and Availability: Is the Money Running Out?

No. The 2026/27 budget is £400 million, and over £560 million was paid out across the first four years of the scheme. Vouchers are issued first come, first served until the financial year's budget cap is reached, but uptake has never come close to that in practice.

Funding is confirmed through to 2029/30, committed in the Warm Homes Plan in January 2026. DESNZ's stated objective is 390,000 installations between 2025/26 and 2029/30. The risk of grant amounts changing is real (they've changed several times), but the risk of running out of money before you can apply is low.

The real constraint isn't funding. It's installer availability. The best MCS installers in many areas have 4–8 week waiting lists. Starting sooner rather than later is about getting a good installer, not beating a funding deadline.

BUS vs Other Grants: Which Should You Use?

BUS isn't the only game in town. Here's how it compares to the other main schemes:

The smart strategy: if you're on qualifying benefits, check ECO4 first, as it may fund insulation and sometimes the heat pump itself, and it shuts on 31 December 2026. In England, check the Warm Homes: Local Grant too, because its income threshold reaches a lot further up than ECO4's benefits test does. If neither applies, BUS is your route. Welsh homeowners can use both BUS and Nest; Scottish homeowners use Home Energy Scotland instead of BUS.

Northern Ireland is the gap. BUS doesn't apply there, ECO doesn't either, and the NI Boiler Replacement Scheme has closed. Check nidirect for what's currently open in your area before assuming any of the figures on this page apply to you.

Combining BUS with Other Support

You can't double-fund the heat pump itself, but you can stack BUS with other forms of support:

• ECO4 or the Warm Homes: Local Grant for insulation: get the fabric work funded first, then apply for BUS for the heat pump. This is the most efficient sequence, and gov.uk confirms prior energy efficiency funding doesn't disqualify you.
• 0% VAT: heat pump installations have been zero-rated for VAT since 1 April 2022 in Great Britain (1 May 2023 in Northern Ireland), and it's already in your quote. Watch the date though: the zero rate ends on 31 March 2027 and reverts to 5% from 1 April 2027, so an installation that slips into the new tax year costs more.
• Mortgage lender cashback: several major lenders run green home improvement cashback offers. Amounts and conditions change constantly, so ask your own lender rather than trusting a figure you read somewhere.
• Smart Export Guarantee: if you add solar panels, you can earn money exporting excess electricity. BUS and SEG are fully compatible. See our solar panel costs guide.
• Heat pump electricity tariffs: tariffs like Octopus Cosy give you cheap windows through the day in exchange for an expensive late-afternoon peak. You'll need your MCS certificate to register.

What Happened to the Home Upgrade Grant (HUG2)?

It's closed. HUG2 was an England-only, council-administered scheme for low-income households off the gas grid, and its delivery window ran from April 2023 to March 2025. gov.uk's page for it is now headed "closed to applications". If you're off grid and on a low income in England, the Warm Homes: Local Grant is the scheme to check now: your council arranges the survey and pays for the work, with no cash cap published per household.

After Installation: What to Do Next

Your heat pump is in. Now what? Most guides stop here, but the first few weeks matter:

Optimise Your Settings

Heat pumps run at lower flow temperatures than gas boilers (45–55°C vs 70–80°C). Your installer should set this during commissioning, but check it hasn't been bumped up. Lower flow temperatures = higher efficiency = lower bills. If your house feels cold, add heating time rather than increasing the temperature, as heat pumps work best running for longer at a lower output.

Register for a Heat Pump Tariff

You're now eligible for time-of-use electricity tariffs designed for heat pump owners. Octopus Cosy, for example, gives you three cheap windows a day (04:00–07:00, 13:00–16:00 and 22:00–00:00) at 51% below the regional day rate, in exchange for a peak between 16:00 and 19:00 at 50% above it. Octopus doesn't publish a single national p/kWh for it, so nobody can honestly tell you what you'll save: it depends entirely on how much of your heating you can shift into those windows, which in turn depends on how well insulated the house is and whether you have a buffer or a big cylinder. You'll need your MCS certificate to register.

Consider Solar Panels

A heat pump + solar panel combination is the most efficient setup for a UK home. Solar generates electricity during the day, your heat pump uses it, and you export any surplus via the Smart Export Guarantee. See our solar panel costs guide and solar + heat pump combo guide for details.

Monitor Your Energy Use

Install a home energy monitor or use your smart meter's in-home display to track consumption. Many heat pump owners find their system runs efficiently for the first winter but could be further optimised. Monitoring helps you spot issues early, such as the heat pump running at times it shouldn't, or the backup immersion heater switching on unnecessarily.

Keep Your MCS Certificate Safe

You'll need it for heat pump tariff registration, for any future insurance claims, and potentially for adding value to your home when selling. It's proof your installation meets required standards.

Is the Boiler Upgrade Scheme Worth It?

Honest answer: if you're on oil or LPG, emphatically yes. If you're on mains gas, the grant makes the upfront cost competitive but the running-cost saving is smaller than most sites pretend, so let's do the arithmetic properly.

Start with the cost of a kilowatt-hour of heat, using the Ofgem price cap for 1 October to 31 December 2026 (electricity 26.32p/kWh, gas 7.97p/kWh) and the UK average heating oil price:

So against mains gas: at a £1,000 net cost you're square in about seven years, at £4,500 you're looking at more like thirty, and at a SCOP of 3.0 rather than 3.5 you're roughly breaking even on running costs and the payback never arrives. The break-even SCOP against a 90% gas boiler is 2.97. A well-designed system running at 35–45°C flow beats that comfortably. A badly designed one running at 60°C might not, which is the whole argument for getting the fabric and the emitters right first.

Against oil it's a different conversation. Roughly £470 a year on the same heat demand pays back a £1,000 net cost in about two years and a £3,000 one in six or seven, and off-grid oil and LPG homes get the larger £9,000 grant until 31 March 2027. If that's you, this is close to a no-brainer.

Two things this table deliberately doesn't do. It doesn't model a heat pump tariff, because Octopus doesn't publish a national rate for Cosy and we're not going to invent one. And it doesn't forecast future prices, because nobody knows: the October 2026 cap period happens to be unusually good for heat pumps because domestic electricity lost its VAT for the winter while gas went up 8.7%, and that particular VAT break ends on 31 March 2027.

Where it's less clear-cut: If your gas boiler is relatively new (under 5 years old) and your property is poorly insulated, the upfront cost may not make financial sense yet. In that case, prioritise insulation now and plan for a heat pump when your boiler reaches end of life.

Next Steps

1. Don't buy an EPC. You don't need one for BUS and haven't since April 2026. If you happen to have one it's a useful list of what's worth doing, but it isn't a requirement and it isn't worth £60–£120 to get one for this
2. Check for free insulation: see if you qualify for ECO4 (Great Britain, closes 31 December 2026) or the Warm Homes: Local Grant (England) before spending anything on insulation
3. Get 3 MCS installer quotes: check credentials at mcscertified.com, and always ask for the heat loss calculation
4. Compare quotes carefully: the cheapest isn't always the best. Look at the specification, not just the price
5. Confirm BUS handling: make sure your chosen installer will submit the Ofgem application on your behalf
6. Model your savings: use our heat pump savings calculator to estimate running costs and payback

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. For the bigger picture on making your home energy-efficient, start with our complete home energy efficiency guide.