Does the Boiler Upgrade Scheme Need an MCS Installer?

The Boiler Upgrade Scheme (BUS) is the one heat pump grant that reaches small business premises, and it runs through the installer. That makes the installer’s certification a funding question as well as a quality one. This page sets out what gov.uk says about how the scheme works for a building used for a business, what that means for choosing an installer, and where the other commercial funding routes stand. For the wider checks, see how to check an MCS heat pump installer and how to choose a commercial heat pump installer.

What the scheme covers for a business

The Boiler Upgrade Scheme (England and Wales) can be used for a building used for a business, not only a home: it pays £7,500 towards an air source or ground source heat pump that replaces a fossil-fuel heating system, within DESNZ capacity caps (45 kWth for a single system, 70 kWth for multiple systems, 300 kWth for shared ground loops), and hybrid systems are excluded. The grant is one per property and is worth £9,000 rather than £7,500 for an air source or ground source heat pump where the property is heated by oil or LPG and has no mains gas connection, until 31 March 2027. Air-to-air heat pumps are residential only.

To be eligible the applicant must own the property, which gov.uk says includes a business, a second home or a property rented to tenants, and must be replacing a fossil-fuel heating system. The installer must commission the system within 120 days of applying. The scheme is open in England and Wales only. Most commercial plant is larger than the caps, so it needs the other routes below.

Why the installer matters: how the application runs

• You contact suitable MCS certified installers to get quotes for the work.
• The installer applies on your behalf on the Ofgem website.
• The value of the grant is taken off the amount you pay for the installation.
• Ofgem contacts you to confirm the installer is acting for you, and may phone or visit to check the installation. MCS may carry out its own checks.

In other words, the grant cannot be applied for directly by the owner, and an installer who is not certified for the right technology is not a route to it. The certification number and body are shown on the installer’s MCS directory listing, which is where to check before any deposit is paid.

What the capacity caps mean in practice

The caps are measured in thermal output: 45 kWth for a single system, 70 kWth for multiple systems and 300 kWth for shared ground loops. A small office, shop, surgery or village hall may fall within them; a care home, hotel, school or industrial unit with a plant room usually does not. The cap applies to the system being funded, so the first question for any business is the design heat load, which comes from the heat-loss survey and not from a rule of thumb. If a bidder proposes a hybrid, remember that hybrids are excluded from the grant.

Because the installer applies for the grant, the installer also needs to know the cap and the eligibility rules, and a competent one will say early whether the building fits. An installer who promises the grant before a survey has been done has not tested the one number that decides eligibility.

Documents to ask for before you pay a deposit

• The MCS directory listing, with certification number and body, for the technology quoted.
• The quote showing the grant as a separate line deducted from the price, not folded into a lower headline figure.
• The design heat load and the system capacity, so the cap can be checked.
• Confirmation of who applies, and the timeline for the 120-day commissioning window.
• Evidence of insurance and the terms of any warranty.

Can I choose my own installer?

Yes, from MCS certified installers, and you should get more than one quote. Compare the bids on the same footing: the sizing basis, the seasonal efficiency to BS EN 14825 at a stated flow temperature, the emitter works and the commissioning. A grant that is deducted from the price makes a quote look cheaper than it is until the exclusions are added back, which is covered in comparing commercial heat pump quotes.

The other commercial routes and their status

The Public Sector Decarbonisation Scheme has had no open application window since Phase 4 closed in November 2024, and gov.uk lists no further phase. The Industrial Energy Transformation Fund closed in July 2025 and gov.uk states that no successor fund is planned. The Green Heat Network Fund runs in application rounds: Round 12 closed on 25 September 2026, so check gov.uk for the next round. Check gov.uk for the current position before relying on any grant; this page records the status on the date shown above.

Tax relief for a heat pump

A heat pump is part of a space or water heating system, which HMRC lists as an integral feature (special-rate plant), and full expensing covers main-rate plant only. The Annual Investment Allowance gives 100% relief up to its limit (£1 million), and companies can then claim a 50% first-year allowance on special-rate plant, with a 6% writing-down allowance on the rest. Confirm the treatment with an accountant.

Questions to ask about funding and insolvency

• Which scheme do you assume in the price, and who confirms my eligibility?
• What is the certification number and body for the technology you are quoting?
• If you stop trading before the work is finished, how are my deposit and stage payments protected?
• Is any warranty insurance-backed, and can I see the policy document?
• Who is responsible for commissioning and for the paperwork that follows?

A guarantee or warranty is only as good as the document behind it, so ask for the document, not the badge. Payments tied to milestones, with a retention until commissioning is proved, protect the building owner in either case. The installer checklist turns these into tick boxes.

Frequently asked questions

Do I need an MCS installer for a business building?

For the Boiler Upgrade Scheme, yes: gov.uk directs applicants to MCS certified installers, who apply on the owner’s behalf. For plant outside the scheme caps, MCS is still a useful check for smaller systems, and larger plant is designed to CIBSE and BSRIA standards.

Can I choose my own installer for the Boiler Upgrade Scheme?

Yes, from MCS certified installers. gov.uk says to contact suitable MCS certified installers to get quotes for the work.

Is the Boiler Upgrade Scheme available for a business?

Sometimes. It can be used for a building used for a business in England and Wales, for a single system within the 45 kWth cap that replaces a fossil-fuel system. Hybrid systems are excluded.

Who applies for the grant?

The installer applies on the owner’s behalf on the Ofgem website, and the value of the grant is taken off the amount the owner pays.

What if the installer goes out of business?

Ask before you sign how deposits and stage payments are protected and whether any warranty is insurance-backed, and ask for the policy document. Link payments to milestones with a retention until commissioning is proved.