UK grants for installing heat pumps with solar panels: eligibility and limits

Part of our guide on how to retrofit a house

What a heat pump and solar panels grant actually covers in the UK

You get £7,500 through the Boiler Upgrade Scheme for an air-source or ground-source heat pump when you own the property in England or Wales, have a valid EPC with no outstanding loft or cavity wall recommendations, and use an MCS-certified installer who claims the grant for you. That figure holds only if the installer discounts it from your invoice and redeems the voucher after commissioning. It does not rise if you add solar.

BUS does not pay for solar PV at all, even when fitted at the same time as the heat pump. Solar is funded elsewhere, usually through ECO4, Home Upgrade Grant Phase 2 (HUG2), or council-led schemes under the Warm Homes Plan umbrella, and those depend on income, benefits, or EPC band. Search the exact wording of heat pump and solar panels grant and you will find bundled adverts that imply one pot covers both. It never does.

Solar helps the heat pump pay back by cutting imported kWh in daylight hours and earning Smart Export Guarantee payments for surplus, typically 2-15p per kWh depending on supplier and tariff at the time you sign. The export rate varies by supplier and contract length, so check the tariff sheet before you fix. Think of the pairing as two separate grants that can run side by side, not a single combined application.

Expect 0% VAT on energy-saving measures including heat pumps and solar until March 2027 in Great Britain, provided the installer supplies and fits them. That relief depends on the installation being in a residential property and invoiced as a single job. Keep that saving separate from grant totals when you compare quotes. Before you commit to anything, it is worth looking at whole house retrofit plan uk in the right order.

Which grants apply when installing heat pumps and solar panels together

ECO4 is the main route that can fund both a heat pump and solar PV in one retrofit, but only if your home is EPC band D to G and you receive a qualifying benefit or meet the ECO Flex income and vulnerability rules set by your council. Funding comes via obligated energy suppliers, not a voucher you hold, and the installer manages the application. The amount depends on property archetype, fuel type and the measures deemed cost-effective, so there is no flat figure.

Great British Insulation Scheme and HUG2 can fund solar and sometimes heat pumps for off-gas or low-income homes, with thresholds set locally. Councils publish their own income caps, often around £31,000-£36,000 household income or council tax band plus EPC criteria, but the exact cap depends on the local authority statement. Check your council's published Flex or HUG2 page for the live figure.

Homeowners who do not meet any means test still have BUS £7,500 for the heat pump and can add solar at full cost, then recover part of the solar cost through SEG export payments. That pairing is common for EPC C homes where ECO4 will not apply. You keep BUS eligibility even if you self-fund solar. We go through cutting emissions with renewables step by step elsewhere on the site.

Smart Export Guarantee is not a grant, it pays for exported kWh after install. Rates differ widely, and the contract you choose fixes the price for 12 months in many cases. Use it to offset running costs, not to fund the upfront build.

• BUS: heat pump only - £7,500 voucher, MCS installer, valid EPC, owner-occupied or small landlord eligible.
• ECO4: heat pump and solar possible - EPC D-G, benefits or Flex, supplier-funded, whole-house assessment.
• HUG2 / Warm Homes Local Grant: solar and heat pump possible - off-gas focus, council-run, income and EPC thresholds vary.
• SEG: export income for solar - supplier tariff, needs MCS solar and export MPAN.

What you'll need

Tuya Energy Meter 1/2 Channel with CT Clamp

Lets you log live watts and total kWh to prove your base load before you size the heat pump and solar.

See the one to get

How combined grant budgets and eligibility criteria work

Most households use one grant per measure, not one budget for the whole job. BUS covers the heat pump up to £7,500 regardless of system size, so a 5-12 kW air-source unit costs the same grant whether you live in a terrace or a detached house. The remaining heat pump cost, any new radiators, hot water cylinder and solar are outside that cap and must be funded separately.

Stacking rules mean you cannot claim BUS and ECO4 for the same heat pump on the same property. If ECO4 funds the heat pump, you cannot also redeem a BUS voucher for it. You can, however, fund the heat pump via BUS and fund solar via ECO4 or HUG2, or vice versa, if you meet each scheme's criteria and the measures are recorded separately with different funding sources. For the detail, see our notes on heat pump retrofit costs and tips.

Budget control sits with the scheme, not you. BUS has a national budget that resets each financial year and vouchers expire after 120 days for air-source and 240 days for ground-source if not redeemed, which depends on how quickly your installer completes and claims. ECO4 and HUG2 are allocated through suppliers and councils, so availability depends on local allocation and installer capacity at the time you apply.

Check grant interaction before you sign. Ask the installer to state in writing which scheme funds which measure, the MCS certificate numbers for each, and what happens if one scheme is withdrawn. That paper trail decides whether you keep eligibility if timelines slip.

Steps to apply for both grants simultaneously

Start with an eligibility sieve before any sales visit. Pull your EPC from the register and note the band, expiry date and any loft or cavity wall recommendations. Gather proof of benefits or income if you aim for ECO4 or HUG2, and confirm you own the property or have landlord permission. That pack decides which path is even open. We cover extracting heat from cold air with heat pump in its own article.

Lock in the installer route next. For BUS you must use an MCS-certified business that will apply for the voucher on your behalf and discount it at invoice. For ECO4 or HUG2 you must use a supplier-approved or council-approved installer who can lodge the ECO measure. Some firms hold both accreditations, which makes a joint install smoother and keeps paperwork in one place.

Apply in the order that protects the rarer funding. If you qualify for ECO4 or HUG2, get that assessment and approval first, because those schemes can cover solar and sometimes the heat pump. Once approved, let the MCS installer apply for BUS for any remaining eligible heat pump not covered by the other grant. Doing it the other way can block ECO4 for the same measure.

• Voucher timing: BUS application happens after you accept the quote, not before you choose an installer.
• Paperwork: keep EPC, MCS certificates, DNO letter and grant offer emails together for future sale or audit.
• Quick test: ask the installer “which scheme pays for which box on the invoice?” If they hesitate, get another quote.

1. Check EPC and fix fails: ensure EPC is valid and outstanding insulation recommendations are addressed or explicitly exempted by the assessor.
2. Screen for ECO4/HUG2: contact your energy supplier or council Flex team with postcode, EPC and benefit or income evidence.
3. Get two written quotes: one showing BUS £7,500 off the heat pump with MCS numbers, one showing ECO4/HUG2 funding for solar with measure codes.
4. Approve and sequence installs: sign only when each quote names its funding source, then schedule solar and heat pump with clear commissioning dates for voucher redemption.
5. Commission and certify: collect MCS certificates, DNO approval for solar, and SEG registration so export payments start.

What EPC and income thresholds decide if you qualify

EPC rules split by scheme. BUS needs a valid EPC issued in the last 10 years with no outstanding recommendations for loft or cavity wall insulation unless you have an exemption, such as a listed wall type or a recent install evidenced by the assessor. There is no minimum EPC band for BUS, so band C homes qualify where ECO4 would not. The other half of this decision is planning eco home budgets.

Income rules only bite on the solar side for most people. ECO4 requires either a qualifying benefit, such as Universal Credit or Pension Credit, or a Flex referral where the council confirms low income, typically £31,000 per household but set locally, or vulnerability criteria. HUG2 and Warm Homes Local Grant focus on households off the gas grid or on low incomes with EPC D to G, and councils publish the exact cap they use that year.

Landlords can use BUS for rental properties in England and Wales, including second homes, but ECO4 and HUG2 are generally for owner-occupiers or private tenants with landlord permission and meeting the same EPC and income tests. That split matters if you plan to do a whole-house retrofit across a portfolio. Each property is assessed separately, not as a landlord average.

Renters cannot claim grants in their own name for a heat pump or solar. The landlord or the energy supplier lodges the claim, and you give consent for works. If you rent, ask the landlord to check ECO Flex with the council first, as that is the only route that can fund both measures without the landlord funding the heat pump via BUS.

Plan a staged retrofit that balances cost, disruption and savings

Plan fabric first, then heat pump, then solar and controls. Most UK homes need 50-100 mm of loft top-up, cavity fill where suitable, and draught-proofing before a heat pump runs at a low flow temperature of 35-45°C for radiators and 45-50°C for hot water. Those temperatures depend on radiator size, insulation level and heat loss, so a room-by-room heat loss survey decides the emitter upgrades, not a rule of thumb alone.

Stage the spend so disruption lands once. If you know you will add solar within 12 months, put the scaffolding, DNO application for 3-6 kW domestic solar, and the consumer unit space for the inverter and generation meter in the same plan as the heat pump cylinder and pipework. Installers can run the solar cable and heat pump electrics on the same scaffold and avoid a second visit to the loft and airing cupboard.

Disruption is mostly inside for the heat pump: new cylinder around 150-300 litres depending on household size, larger radiators or fan coils where heat loss is high, and condensate routing. Solar is mostly outside: roof hooks, rails and inverter mounting. Do noisy inside works together and finish with commissioning, MCS certificates and SEG setup so you can monitor import versus export from day one.

Test before you commit to battery size. Run the heat pump for a month and log daily kWh with a clip-on monitor, then size solar to cover your daytime base load plus a share of heat pump draw in shoulder months. That measured profile beats any generic calculator and stops you buying storage you will not cycle in winter.

Quick questions

I sized the solar after logging a month of heat pump use with a clamp meter, which cut the quote by one panel and one radiator upgrade.