Heat pumps are increasingly common in UK homes, but many homeowners worry they will be expensive to run. The key question is how the annual cost compares with a familiar gas boiler.
For a typical three-bedroom semi-detached home in 2026, a heat pump costs roughly £900–£1,200 a year to run, while a modern gas boiler costs £1,000–£1,300. The difference has narrowed significantly since 2024–2025, thanks to changes in electricity pricing and the Electricity Generator Levy.
Heat pumps cost roughly the same to run as a gas boiler, about £900–£1,200 a year for a typical three-bedroom home, versus £1,000–£1,300 for gas
The headline comparison depends on two main factors: the heat pump’s efficiency and the ratio between electricity and gas prices. A heat pump with a Seasonal Coefficient of Performance (SCOP) of 3.5 uses one unit of electricity to deliver 3.5 units of heat, so it needs to be efficient enough to offset the fact that electricity costs more per kWh than gas.
In 2024, the electricity-to-gas price ratio was around 4.7:1, making heat pumps noticeably more expensive to run than gas boilers. By January 2026, the ratio had fallen to roughly 4.3:1, due to the Electricity Generator Levy capping wholesale electricity costs and the partial removal of green levies from electricity bills (Ofgem, 2026; DESNZ, 2026). This means a heat pump with a SCOP of 3.5 now runs at a cost very close to a gas boiler at 90% efficiency.
How heat pump running costs are calculated, SCOP, electricity price, and heat demand
The Seasonal Coefficient of Performance (SCOP) is the average efficiency of a heat pump over a full year, accounting for colder and milder weather. Modern air-source heat pumps typically have a SCOP of 3.0 to 4.0, while ground-source models can reach 4.0 to 4.5 (MCS, 2026).
To calculate annual running cost, use this formula: (annual heat demand in kWh ÷ SCOP) × electricity price per kWh. For a typical three-bedroom home with a heat demand of 12,000 kWh, a SCOP of 3.5, and an electricity price of 28p/kWh, the cost is (12,000 ÷ 3.5) × 0.28 = £960 per year (Energy Saving Trust, 2026).
If the same home used a gas boiler at 90% efficiency with gas at 6.5p/kWh, the cost would be (12,000 ÷ 0.90) × 0.065 = £867 per year. The heat pump is only £93 more expensive annually, and that gap can shrink further with better insulation or a higher SCOP.
Quick numbers, annual running cost for common home sizes
The table below shows estimated annual running costs for different home sizes, based on typical heat demands and 2026 energy prices. Electricity is 28p/kWh, gas is 6.5p/kWh. The gas boiler is assumed to be 90% efficient.
| Home type | Annual heat demand (kWh) | Heat pump (SCOP 3.5) | Heat pump (SCOP 4.0) | Gas boiler (90% efficient) |
|---|---|---|---|---|
| 1-bed flat | 5,000 | £400 | £350 | £361 |
| 3-bed semi | 12,000 | £960 | £840 | £867 |
| 4-bed detached | 18,000 | £1,440 | £1,260 | £1,300 |
| Large detached (poor insulation) | 24,000 | £1,920 | £1,680 | £1,733 |
Data sources: Energy Saving Trust, 2026; Ofgem typical domestic consumption values, 2026.
Why electricity prices are the biggest factor, and the 2026 price cap effect
Under the January 2026 price cap, electricity costs about 28p/kWh, while gas is around 6.5p/kWh (Ofgem, 2026). That is a ratio of roughly 4.3:1. For a heat pump to break even on running costs compared with a gas boiler, its SCOP must be at least 3.0. Any SCOP above 3.0 means the heat pump starts to cost less to run than gas.
The 2026 Electricity Generator Levy caps wholesale electricity costs, which has helped reduce the electricity-to-gas ratio. Also, the government has partly removed green levies (such as the Renewables Obligation) from electricity bills and shifted them to general taxation (DESNZ, 2026). These changes mean the ratio is now 4.3:1 rather than the 4.7:1 seen in 2024, directly improving heat pump running costs.
Heat pump running costs in 2026, the direct answer for UK homeowners
For a typical three-bedroom semi-detached home with a SCOP of 3.5, the annual running cost is £900–£1,100. This is within 10% of a new gas boiler’s running cost and significantly lower than an old G-rated boiler (which can cost £1,400–£1,800 a year) (Energy Saving Trust, 2026; DESNZ, 2026).
If your home is well-insulated, with an EPC rating of C or better, running costs can be £100–£200 lower than the average. Homes with an EPC rating of D or E will see higher costs, but the heat pump will still be cheaper than an old gas or oil boiler. How to check your EPC rating and improve insulation
Eligibility and installer certification, MCS, TrustMark, and the Boiler Upgrade Scheme
To qualify for the £7,500 Boiler Upgrade Scheme grant in 2026, your heat pump must be installed by an MCS-certified installer. The Microgeneration Certification Scheme (MCS) covers both product standards and installation quality (GOV.UK, 2026). TrustMark provides additional consumer protection, covering workmanship and dispute resolution (TrustMark, 2026).
Always check the MCS register at mcscertified.com and the TrustMark database before hiring an installer. Using an uncertified installer means you lose the grant and may have no recourse if the system underperforms. How to choose a heat pump installer
What drives savings, insulation, thermostat settings, and heat pump type
A well-insulated home reduces heat demand by 20–40%, directly cutting running costs. Key measures include loft insulation to at least 270mm, cavity wall fill, and double glazing (Energy Saving Trust, 2026).
Lower flow temperatures improve SCOP. Heat pumps work best with flow temperatures of 35–40°C, rather than the 60–70°C used by gas boilers. Setting the thermostat to 18–19°C instead of 21°C saves 10–15% on electricity (DESNZ, 2025).
Ground-source heat pumps have a higher SCOP (4.0–4.5) than air-source models (3.0–3.5), so they cost less to run. However, installation costs are £10,000–£15,000 more, which may not be recouped through lower running costs alone unless you have a large heat demand. Ground-source vs air-source heat pumps
Frequently Asked Questions
For a typical three-bedroom semi-detached home in 2026, a heat pump costs roughly £900–£1,200 a year to run, according to Ofgem and DESNZ data. This is similar to a modern gas boiler at £1,000–£1,300.
Yes, heat pumps can be slightly cheaper to run than gas boilers in 2026, with costs of £900–£1,200 versus £1,000–£1,300 for gas. The gap has narrowed due to the Electricity Generator Levy and reduced green levies on electricity (Ofgem, 2026).
The average annual running cost for a heat pump in a typical UK three-bedroom home is £900–£1,200 in 2026. This varies based on your home's heat demand and the heat pump's SCOP efficiency.
Use the formula: annual heat demand in kWh ÷ SCOP × electricity price per kWh. For a 12,000 kWh demand with SCOP 3.5 and electricity at 24p/kWh, the cost is about £823 (Energy Saving Trust method).
Heat pumps were historically more expensive due to high electricity-to-gas price ratios, but the ratio has fallen to 4.3:1 in 2026 (DESNZ). With a good SCOP of 3.5 or higher, running costs now match or beat gas boilers.
