Are Heat Pumps Worth It in the UK?

Give each system the same job: 10,000kWh of useful space heat a year. Use electricity at 26.32p/kWh, gas at 7.97p/kWh, an existing gas boiler at 85% efficiency and a heat pump with seasonal performance of 3.0.

On these assumptions, the heat pump saves about £1,755 a year against direct electric, but only about £60 against the gas boiler. That is a completely different investment decision.

These are illustrative space-heating energy costs, not whole bills or forecasts. The tariff figures are Ofgem’s GB-average Direct Debit default-tariff rates for 1 October–31 December 2026. Heat demand and system performance are assumptions. Standing charges, hot water, installation, maintenance and finance are excluded; use your own rates, especially in Northern Ireland.

Seasonal performance tells you how much heat you get for each unit of electricity over a season. We use it here as a planning assumption, not a guaranteed result.

At these prices, the heat pump needs seasonal performance of about 2.8 to match the 85%-efficient boiler’s space-heating energy cost. Against a 90%-efficient boiler, the threshold is about 3.0. These thresholds exclude standing charges and other costs.

A quote that only works at the best-case performance is not a strong financial case.

Ask the installer to explain the expected performance for your home, then model a lower result as well.

If your current system can stay, switching means paying for a new installation now. If replacement is unavoidable, the relevant cost is usually the difference between the two complete replacement options.

In a purely illustrative example, a £3,000 extra outlay with £60 annual savings takes about 50 years to recover through those savings alone. At £280 a year, it is about 11 years. This is simple arithmetic, not a lifetime forecast: prices, maintenance, equipment life and finance can change the result.

Deduct only funding you have confirmed you qualify for. Support varies by nation and scheme; a loan still has to be repaid. Ask for the total installed price, eligible grant and amount you pay to be shown separately.

Include radiator changes, hot-water arrangements, electrical work and any gas-disconnection costs that apply. A cheap headline quote is not a complete comparison if essential work sits outside it.

• Your annual useful heat demand and how it was estimated.
• Expected seasonal performance, flow temperatures and a lower-performance case.
• The complete installation scope, including radiators and hot water.
• Net upfront cost after confirmed grant support, plus maintenance and finance.
• A comparison against keeping or replacing your actual existing system.
• Space, noise and siting requirements assessed for your home.

Use the Complete Heat Pump Guide for the practical questions behind the quote.

For a home using standard-rate direct electric, we would investigate seriously. For a boiler that needs replacing, get both options priced. For a working gas system, avoid rushing into an upgrade on the promise of large savings that the numbers do not support.

A heat pump is an upgrade. Whether it is a good investment depends on what it replaces.