Financing a Heat Pump in 2026: Loans, Green Mortgages and ECO4

The upfront cost of a heat pump — typically £10,000–18,000 for an air source installation — is the single biggest barrier for most homeowners. But there are more ways to finance one than most people realise. Between the BUS grant, 0% VAT, government-backed interest-free loans, ECO4, green mortgages, and supplier finance, the total available support can significantly reduce or defer the out-of-pocket cost. Here is the full landscape as of April 2026.

The BUS grant: the starting point

The Boiler Upgrade Scheme provides £7,500 towards the cost of an air or ground source heat pump in England and Wales. This is a grant — not a loan — that is deducted from your invoice before you pay. It is applied by your MCS-certified installer directly; you do not need to apply or handle any money. The grant is available until March 2028 and is funded regardless of your income.

Combined with 0% VAT on heat pump installations (in place until at least March 2027), the effective value of government support is £8,000–10,000 on a typical installation — a significant reduction from the headline price.

Government-backed interest-free loans

In Scotland, Home Energy Scotland offers interest-free loans of up to £7,500 to cover costs after the cashback grant. England does not currently have a direct equivalent, but the Great British Insulation Scheme can fund insulation improvements that may accompany a heat pump installation. The government has also signalled its intention to introduce a Pay-As-You-Save (PAYS) scheme under the Warm Homes Plan, where repayments are tied to energy bill savings — details were still being consulted on as of April 2026.

ECO4: support for eligible lower-income households

The Energy Company Obligation (ECO4) scheme, running until March 2026 (with successor schemes expected), requires energy suppliers to fund heating and insulation improvements for lower-income households. Heat pumps are an eligible measure under ECO4 for households meeting the income or benefit criteria. If eligible, the full cost of the heat pump and associated works can be covered with no contribution from the homeowner.

Green mortgages and further advance

Several major lenders — including Barclays, NatWest, Halifax, and Nationwide — offer green mortgages or green further advance products at preferential rates for energy-efficiency improvements. A further advance allows you to borrow additional money on your existing mortgage to fund a heat pump, often at a lower rate than a personal loan. Interest rates on green further advances typically run 0.1–0.5% lower than standard further advance rates.

The drawback is that you are adding to secured debt, extending the period over which interest accumulates. For larger loan amounts, a green further advance can work out cheaper than a personal loan, but the total interest paid over a 10–15 year mortgage extension may exceed that of a shorter-term personal loan. Run the numbers for your specific situation before committing.

Installer finance and 0% deals

Many larger heat pump installation companies offer point-of-sale finance, often 0% for 12–36 months, arranged through third-party lenders. These products are particularly useful for spreading the cost after the BUS grant is applied — for example, financing the remaining £5,000–8,000 of a £12,500 installation (post-grant) over 24 months interest-free. The catch: after the 0% period, a high-rate term loan kicks in. Always ensure you can repay in full before the promotional period ends or refinance at that point.

Personal loans

For homeowners who do not qualify for green mortgage products or prefer not to secure debt against their property, personal loans from banks or building societies are a straightforward option. At April 2026 rates, representative APRs for personal loans of £5,000–10,000 range from approximately 6–10% over 3–5 years. The total interest cost on a £7,000 loan at 8% over 4 years is approximately £1,180 — modest relative to the lifetime running cost savings the heat pump delivers.

Combining sources

The most cost-effective approach for most homeowners is to combine the BUS grant (reducing the invoice directly) with installer 0% finance for the remaining amount, then repay that finance from the energy bill savings the heat pump generates. A heat pump replacing an oil boiler might save £400–700/year on fuel — enough to service a £5,000 loan in 7–12 years, after which the savings accumulate purely as cash in hand.