Many UK homeowners are looking for the cheapest way to heat their home this winter. With energy prices still high, the choice of heating system has a significant impact on your annual bills.
The cheapest way to heat a UK home this winter is with an air source heat pump, provided your home is well insulated. According to the Energy Saving Trust, a typical three-bedroom home with good insulation can expect annual running costs of around £930 for an air source heat pump, compared to £1,200 for mains gas and over £2,000 for electric storage heaters (Energy Saving Trust, 2026).
The cheapest way to heat a UK home this winter is a heat pump, but only if your home is well insulated
An air source heat pump works by extracting heat from the outside air and transferring it inside. The key measure of its efficiency is the coefficient of performance (COP), which for modern models is typically between 3 and 4. This means for every 1 kWh of electricity used, the pump delivers 3 to 4 kWh of heat.
The keyword “cheapest way to heat home” is answered by the heat pump, but only when the property has adequate insulation. The Energy Saving Trust states that you need loft insulation to 270mm, cavity wall fill, and effective draught-proofing for the heat pump to operate at its most efficient (Energy Saving Trust, 2026). The cost advantage disappears if the home loses heat faster than the pump can efficiently supply it. The EST reports that poorly insulated homes can see running costs rise by 30–50% for heat pumps.
For homes without these insulation upgrades, mains gas remains the cheapest option. The EST reports average annual gas heating costs of £1,200 for a typical home with a modern condensing boiler (Energy Saving Trust, 2026).
Eligibility for the Boiler Upgrade Scheme (BUS) and who qualifies
The Boiler Upgrade Scheme (BUS) is the main government grant for heat pumps. It offers £7,500 off the installation cost for an air source or ground source heat pump (GOV.UK, 2026).
You qualify for the BUS if you own the property or have written permission from your landlord. Your home must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation. You must be replacing a fossil fuel heating system, such as gas, oil, LPG, or electric storage heaters.
You do NOT qualify if your EPC has outstanding insulation recommendations that you have not addressed. You also cannot claim the grant for a heat pump installed in a new-build property. Social housing tenants without landlord consent are not eligible.
The scheme operates on a first-come, first-served basis until funds are exhausted. The Department for Energy Security and Net Zero reported that in 2025/26, funding was fully allocated by February (DESNZ, 2026).
Quick numbers, running costs and grant amounts
| Heating type | Average annual running cost (typical 3-bed home) | Upfront cost (new system) | Grant available |
|---|---|---|---|
| Mains gas boiler | £1,200 | £2,500–£3,500 | None |
| Oil boiler | £1,600–£2,000 | £3,000–£5,000 | None |
| LPG boiler | £1,800–£2,200 | £3,000–£5,000 | None |
| Electric storage heaters | £2,000+ | £1,500–£3,000 | None |
| Air source heat pump (with BUS grant) | £930 | £7,000–£13,000 | £7,500 |
| Ground source heat pump (with BUS grant) | £850 | £14,000–£19,000 | £7,500 |
Running costs are from Energy Saving Trust figures for a typical semi-detached home with four bedrooms and good insulation (Energy Saving Trust, 2026). Grant amounts are from the GOV.UK Boiler Upgrade Scheme page (GOV.UK, 2026). Upfront cost estimates are from MCS installer directory average quotes for 2026 (MCS, 2026).
What a heat pump installation requires for eligibility
To qualify for the BUS grant, you must use an MCS-certified installer. You can check the MCS Installer Directory at mcscertified.com for installers in your postcode (MCS, 2026). The installer must issue an MCS certificate and a Microgeneration Certification Scheme (MCS) compliance document after the installation.
Your property must have a minimum EPC rating of D or better for the heat pump to be eligible for the grant (GOV.UK, 2026). The system must be installed in line with MIS 3005 for air source heat pumps or MIS 3006 for ground source heat pumps. These standards cover design, installation, and commissioning requirements.
Your installer will also need to check that your existing radiators are large enough to work efficiently with the lower flow temperatures of a heat pump. In many cases, radiators may need to be upgraded to larger or more efficient models.
guide to heat pump installation requirements
How to verify an installer, MCS, TrustMark, and Gas Safe Register
For heat pumps, use the MCS Installer Directory. Only MCS-certified installers can issue the certificate needed for the BUS grant. For gas boilers, check the Gas Safe Register at gassaferegister.co.uk. It is illegal for an uncertified person to install a gas boiler (Gas Safe Register, 2026).
For oil boilers, check OFTEC registration at oftec.org. OFTEC registration is required for oil-fired heating installations. For all heating work, TrustMark at trustmark.org.uk provides a government-endorsed quality mark for tradespeople, including heating installers (TrustMark, 2026).
Always request proof of certification before any work begins. The installer must provide their registration number, which you can verify online. Never pay the full amount upfront for any heating installation.
What to do if you do not qualify for a heat pump grant
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. GOV.UK confirms this offers free or subsidised loft and cavity wall insulation for low-income households (GOV.UK, 2026).
If you cannot install a heat pump due to lack of outdoor space or listed building restrictions, the cheapest remaining option is a modern condensing gas boiler with a smart thermostat. EST data shows this can reduce gas usage by 15–20% compared to an older boiler (Energy Saving Trust, 2026).
For off-gas homes, a modern oil or LPG boiler with a smart controller is the next cheapest option. Running costs are still around £1,600–£2,000 per year according to EST 2026 figures. Consider a heat pump even without the grant. The EST calculates that at current electricity-to-gas price ratios of 3.5:1, a well-insulated home can still break even within 7–10 years on running costs alone.
guide to the Great British Insulation Scheme
How to confirm your home’s eligibility before you apply
Start with your EPC. Check it at gov.uk/find-energy-certificate. Look for any insulation recommendations marked as “not installed”. You must address these before applying for the BUS grant.
Get a free energy advice visit from your local Energy Advice Scotland, Energy Saving Trust, or Simple Energy Advice service. These are DESNZ-funded services available in 2026. Use the EST online “Home Energy Check” tool to estimate your current heating costs and potential savings from a heat pump.
Contact an MCS-certified installer for a site survey. They will assess your home’s heat loss, check for space for an outdoor unit, and evaluate compatibility with existing radiators. This survey is typically free and gives you a clear picture of whether a heat pump is suitable for your home.
