Heat Pump vs Gas Boiler Running Costs
The gas-to-electricity price gap has narrowed, and it changes which system actually wins on cost.
At the Jul-Sep 2026 Ofgem price cap (26.11p/kWh electricity, 7.33p/kWh gas)1, a gas boiler costs about £977 a year to heat a medium UK home, while a heat pump costs £1,044 at SCOP 3.0 but only £895 at SCOP 3.5 and £783 at SCOP 4.0. The breakeven point is around SCOP 3.2: above that, a heat pump is cheaper to run than gas even before counting carbon savings.
The numbers (medium 3-bed house, 12,000 kWh/year heat demand)
| System | Efficiency | Energy used | Annual cost |
|---|---|---|---|
| Gas boiler | 90% efficient | 13,333 kWh gas | £977/year (at 7.33p/kWh) |
| Heat pump (SCOP 3.0) | 300% efficient | 4,000 kWh electricity | £1,044/year (at 26.11p/kWh) |
| Heat pump (SCOP 3.5) | 350% efficient | 3,429 kWh electricity | £895/year (at 26.11p/kWh) |
| Heat pump (SCOP 4.0) | 400% efficient | 3,000 kWh electricity | £783/year (at 26.11p/kWh) |
Medium UK home, 12,000 kWh/year heat demand, standard variable rates (Ofgem price cap, 1 Jul-30 Sep 2026: 26.11p/kWh electricity, 7.33p/kWh gas). Gas boiler assumed 90% efficient. Excludes standing charges.
Why the difference matters
The electricity-to-gas price ratio sets the breakeven point. In Jul 2026, electricity costs 3.6× gas per kWh (26.11p vs 7.33p)1. Multiply that ratio by boiler efficiency (90%) and you get a breakeven SCOP of about 3.2. Since many well-designed 2026 installations reach SCOP 3.5-4.02, gas no longer has the clear cost advantage it had when the electricity-to-gas ratio was closer to 4.5-5× during 2023-2025. Underperforming systems at SCOP 2.5-3.0 still lose to gas on pure running cost.
When heat pumps win on cost
- High SCOP systems (3.5+): well-designed installations with low flow temperatures in reasonably insulated homes.
- Time-of-use tariffs: off-peak electricity around 14.5p/kWh (see our tariff guide) pushes the breakeven SCOP even lower.
- No gas connection: homes on oil or LPG heating almost always save with a heat pump; those fuels cost more per kWh than mains gas.
- Gas price spikes: the 2022-23 crisis saw gas well above 10p/kWh, which would have made almost any heat pump cheaper to run.
Installation cost difference
A gas boiler costs roughly £2,000-3,500 installed. An air source heat pump costs £8,000-15,0003. The UK Boiler Upgrade Scheme offers a £7,500 grant towards an air or ground source heat pump in England and Wales, deducted at the point of sale with no means test4, which narrows most quotes to roughly £500-6,500. From 21 July 2026, some off-gas-grid properties qualify for an increased £9,000 grant. Payback depends on lifespan too: heat pumps typically last 15-20 years against 10-15 for a boiler.
Carbon emissions
This comparison is cost-only. On carbon, heat pumps win clearly even where the cash saving is marginal. At current UK grid carbon intensity, a heat pump running at SCOP 3.5 cuts heating emissions by roughly 60-70% compared with a gas boiler, and that gap widens every year as the grid adds more renewable and nuclear generation.
- Gas boiler annual cost
- £977
- Heat pump cost, SCOP 3.5
- £895
- Breakeven SCOP
- ~3.2
- Boiler Upgrade Scheme grant
- £7,500
Frequently asked questions
What SCOP does a heat pump need to beat a gas boiler on running cost?
At the Jul-Sep 2026 Ofgem price cap, roughly SCOP 3.2 or higher on a standard variable electricity tariff. A well-designed system at SCOP 3.5 to 4.0 comfortably beats gas; an oversized or poorly commissioned system at SCOP 2.5 to 3.0 can cost more.
Does a heat pump always cost more to install than a gas boiler?
Yes, before grants. A gas boiler typically costs £2,000-3,500 installed; an air source heat pump costs £8,000-15,000. The £7,500 Boiler Upgrade Scheme grant narrows the gap to roughly £500-6,500 for many homes.
Are heat pumps cheaper for carbon emissions even if not for cash?
Yes. At current UK grid carbon intensity, a heat pump at SCOP 3.5 cuts heating carbon emissions by roughly 60-70% compared with a gas boiler, and the gap widens as the grid keeps decarbonising.
Related guides
Sources
- Ofgem, Changes to the energy price cap between 1 July and 30 September 2026, accessed 3 Jul 2026
- Energy Saving Trust, Heat pumps: how they work, costs and savings, accessed 3 Jul 2026
- Checkatrade / MyJobQuote, Air source heat pump installation cost guides, accessed 3 Jul 2026
- GOV.UK, Apply for the Boiler Upgrade Scheme: what you can get, accessed 3 Jul 2026
Compare for your home: Run the heat pump cost calculator with your actual energy rates.
Last reviewed: 3 July 2026. Figures follow the Ofgem quarterly price cap and will be updated at the next review.