Free heat pump for a flat with a gas boiler: is yours eligible?

If your flat has a gas boiler, often a combination (combi) boiler that also heats your taps, you may be wondering whether you can swap it for a heat pump without paying. This article covers what the scheme says about gas heating, why the boiler cannot stay, and what ByEco’s free survey (assessment) works out. If your flat may be eligible, it sits alongside our guides to free heat pumps for flats, free heat pumps for 1 and 2 bedroom flats and replacing a working boiler.

Can an eligible flat with a gas boiler get a free heat pump?

It may, if your flat is eligible. Having a gas boiler does not rule a flat out: the scheme is built to replace fossil fuel heating, and gas is the first example Ofgem gives. The installer must take the £7,500 grant off the quote before you pay anything. If the quote for your flat is no more than the grant there may be nothing left to pay, and if it is more you would pay the difference. Which applies depends on your flat, so we cannot promise it in advance.

What matters for a gas-heated flat is not the fuel. It is whether the flat can work with a heat pump once the boiler is gone: where the unit goes, what heats the rooms and how you get hot water. That is what the free survey answers. See which homes may get a free heat pump.

What the rules say about gas heating

The Boiler Upgrade Scheme regulations say that where a property already had a heating system, the system providing space heating or water heating must be fuelled by fossil fuel or be an electric heating system. Ofgem’s glossary defines fossil fuel as including natural gas, and Ofgem’s installer guidance gives gas first among its examples of the previous system. GOV.UK’s eligibility page says you must be replacing fossil fuel heating systems such as oil, gas, electric or LPG. We found nothing in these sources that treats one type of gas boiler differently from another, so the rule is about the fuel, not about whether your boiler is a combi.

Two more points apply. If the previous heating system includes a heat pump providing space heating, the property is not eligible. And Ofgem’s list of what an application must include asks for the fuel type of the heating system being replaced and for confirmation of whether the property is connected to the gas grid, so expect your installer to ask both.

The gas boiler has to be replaced, not kept

This is the part that surprises people. The grant is for replacing your heating system, not adding to it. Ofgem says that when you install a grant-funded system it must fully replace the property’s existing fossil fuel or electric heating system, except where supplementary heating appliances are permitted under the scheme. Those permitted appliances must not be fossil fuel based, so a gas boiler cannot be one of them.

• No hybrid. GOV.UK says you cannot get a grant for a hybrid heat pump system, for example a combination of gas boiler and air source heat pump. Ofgem says heat pumps installed alongside a separate fossil fuel boiler, including retrofit hybrids, are ineligible. See our guide to hybrid heat pumps.
• The heat pump must stand on its own. Ofgem says it must have enough thermal capacity to meet the full space heating demand of the property by itself.
• Some parts can stay. Ofgem says you do not need to remove every part of the existing heating system, and that components can be kept if they are in good condition and suitable for the new installation. Its list includes pipework, radiators or other heat emitters, and heating controls such as thermostats and timers.

What happens to the gas supply, the old boiler’s connections and anything else attached to it is a different question. None of the scheme sources we read says, so we do not guess. Ask your installer to set it out in writing, and see what happens to your gas supply after a heat pump.

What the free survey and heat loss calculation decide

ByEco’s free survey (the assessment) is where these questions get answers for your flat. According to ByEco’s brochure, we visit, measure each room and look at the walls, windows, radiators, pipework, electrics and where a unit or vents could go, and a room-by-room heat loss calculation then sets the kW size needed and whether any radiators should change.

• Radiators and pipework. If your flat already has radiators and pipework, that is the starting point. Whether they suit a heat pump is a design question: MIS 3005-D, the MCS heat pump design standard, asks for performance data from the heat pump manufacturer and the emitter system designer, and says the customer must be given the type and dimensions of the emitters in writing before installation starts. The MCS heat emitter guide (MCS 021) shows how a radiator’s output against a room’s heat loss sets the water temperature needed, and gives reducing the room’s heat loss or fitting a radiator with a higher output as ways to improve the result. See whether you need new radiators.
• Where the unit and its openings go. ByEco’s brochure says its indoor units need two circular openings through the external wall, one for the air inlet and one for the air outlet, and that the final opening sizes, positions and terminal type are confirmed on site and set out in your quote and drawings. See heat pumps without an outdoor unit.
• Hot water. Your gas boiler may be what heats your taps now. Ofgem says a grant-funded heat pump must be capable of providing the full space heating and hot water heating demand of the property, either on its own or in combination with permitted supplementary appliances. How hot water would be provided in your flat is something the survey confirms, and ByEco’s brochure says the quote sets out the hot water arrangement in writing. See heat pumps and hot water.
• The electricity supply. MIS 3005-D requires the installer to ensure the electricity supply is adequate for the size of heat pump specified. ByEco’s brochure lists a single-phase electrical supply for its indoor units. See heat pumps and your electricity supply.

For what the visit involves, see what to expect from a heat pump survey.

Ownership, shared ownership and the lease

Owners and landlords. GOV.UK’s test is that you own the property you are applying for, including a second home or a property you rent out to tenants. Letting the flat? See heat pumps for landlords.

Shared ownership. The regulations exclude social housing, using the meaning in section 68 of the Housing and Regeneration Act 2008. Ofgem’s guidance describes social housing as homes owned or managed by councils, housing associations or other organisations providing housing at below market rent or through shared ownership schemes for people in housing need. So a shared ownership flat is excluded only if it counts as social housing in that sense. The regulations do not exclude shared ownership by name, but Ofgem’s list of what an application must include has a declaration worded “that the property is not social housing or has shared ownership” (the wording is ambiguous), so treat a shared ownership flat as unlikely to qualify until the survey confirms it.

A shared boiler. If your flat is heated from a boiler that serves several flats rather than from its own, tell us at the start. Ofgem says multi heat pump (cascade) systems heating multiple unrelated properties, such as flats, are not eligible, but the sources we read do not address a flat whose current heating comes from a boiler shared with other flats, so the survey is where it is checked.

The lease and the freeholder. We found no Boiler Upgrade Scheme source, in GOV.UK’s pages or Ofgem’s guidance, that states freeholder consent as a condition of the grant. Your lease is a separate matter and may require permission for work to the building or its outside walls. Bring it to the survey and read permission for a heat pump in a flat.

What the grant covers

GOV.UK lists £7,500 towards an air source (air-to-water) heat pump, and describes the scheme as a grant to cover part of the cost of replacing fossil fuel heating systems. Ofgem says the installer must deduct the full grant from the quote before you pay. ByEco’s offer for eligible 1 and 2 bedroom flats is described in the offer box at the top of this page. The quote you receive after the survey confirms whether anything is left to pay and whether any radiator, pipework or electrical work is included. For the detail, read our Boiler Upgrade Scheme guide.

What to have ready and what happens next

Ofgem says evidence of the previous heating system would typically include a recent utility bill or fuel receipt and photographs of it, ideally gathered from the owner in advance. For gas heating, the bill must be dated within the last 3 months, show the installation address, and include all pages or show usage figures. The photographs must clearly show the heat source, such as a gas boiler, its make and model, for example the nameplate, and its location.

Because Ofgem asks for photographs of the existing system, and accepts alternative evidence only in limited cases where it has already been removed, it is sensible to leave your boiler where it is until your installer has photographed it.

1. Get in touch for your free survey. Tell us it is a flat, that it has a gas boiler, and whether you own it outright, own a share or rent it out.
2. The survey and heat loss calculation. Ofgem requires the installer to carry out an on-site assessment and be satisfied the property and technology meet the eligibility requirements. ByEco’s brochure says the heat loss calculation sets the kW size and whether any radiators should change.
3. The quote. It shows the grant deducted. You decide whether to go ahead, and you can say no.
4. The application. GOV.UK says the installer applies on your behalf on the Ofgem website. Ofgem emails you for consent, and you must use the link within 14 days or the application will expire and may be rejected.
5. Ofgem decides. Ofgem issues a boiler upgrade voucher once the application is properly made, and must refuse it where it is not satisfied the conditions are met.
6. Installation. The work has to be done within the voucher’s validity, explained below.

Why it is sensible to ask early

The Boiler Upgrade Scheme is not permanent. The sources say:

• Final date. The regulations say Ofgem must refuse to issue a voucher after 31 December 2029.
• Budget. Ofgem cannot issue new vouchers once the budget threshold is met. If the available budget runs out, Ofgem may operate a queue, ordered by when an application is deemed properly made. Separately, the Secretary of State may introduce a cap on the number of vouchers issued each quarter.
• Voucher validity. An air-to-water voucher expires three months after it is issued, and an expired voucher cannot be extended, although the installer can re-apply for a new one. GOV.UK words the limit differently, as 120 days from applying, so plan around whichever limit comes first.

Ofgem’s BUS monthly scheme update, with statistics to 31 October 2026 and last updated on 11 November 2026, lists £62,665,000 as the remaining budget for Year 5 (1 April 2026 to 31 March 2027). Ofgem’s footnote says that figure includes all undetermined applications and vouchers issued yet to be redeemed, and is a dynamic value. It is a snapshot, so check the latest report. We are not forecasting when funds might be used.

So asking for your free survey sooner means your application can be made while funding is available, if your flat is eligible. Rules and funding can change.

Where ByEco stands

Call 0161 710 4510 or use the contact page and tell us the flat’s area, that it has a gas boiler and who owns it. The survey is free, and it is how we find out whether your flat is eligible. See also our heat pumps and grants pages, or get in touch for your free survey.

Worth asking any installer: what happens to my gas boiler and its connections, how will my hot water be provided, which radiators and pipework would my flat need, are they in the quote, and what does the contract say if my application is rejected? Ofgem says the installer’s ability to seek payment of the deducted amount then depends on the contract between you and the installer.

Sources

Every figure on this page was checked against primary sources on 11 November 2026. Grant rules, planning rules and prices change — if you are reading this much later, verify before acting.

• GOV.UK — Apply for the Boiler Upgrade Scheme: overview
• GOV.UK — Apply for the Boiler Upgrade Scheme: what you can get
• GOV.UK — Apply for the Boiler Upgrade Scheme: check if you’re eligible
• GOV.UK — Apply for the Boiler Upgrade Scheme: how to apply
• Ofgem — Boiler Upgrade Scheme: guidance for installers
• Ofgem — Boiler Upgrade Scheme guidance for installers V5.2 (PDF)
• Ofgem — BUS monthly scheme update
• legislation.gov.uk — Boiler Upgrade Scheme (England and Wales) Regulations 2022, regulation 5
• legislation.gov.uk — Boiler Upgrade Scheme (England and Wales) Regulations 2022, regulation 15
• MCS — MIS 3005-D The Heat Pump Design Standard, Issue 3.0
• MCS — MCS 021 Heat Emitter Guide for Domestic Heat Pumps, Issue 2.1