Heat Pump vs Gas Boiler: Which Costs Less Over 10 Years?
A heat pump costs roughly £11,700–£16,000 over 10 years (with the £7,500 BUS grant), while a gas boiler comes in at £11,600–£15,000. The gap is tight. Your boiler's on its last legs, everyone says get a heat pump, your plumber says stick with gas. Here's the full breakdown to help you decide.
James Carter
Written by James Carter, energy specialist
The short answer
For a well-insulated home with the £7,500 BUS grant, a heat pump will cost you less over 10 years. For a poorly insulated Victorian terrace, a gas boiler is still the more practical and affordable choice - for now.
Heat pump vs gas boiler upfront costs
A mid-range combi gas boiler costs £1,500–£2,500 installed. An air source heat pump costs £8,000–£14,000 installed. On paper, gas wins by a mile.
But the Boiler Upgrade Scheme (BUS) grant gives you £7,500 off a heat pump. That brings the realistic cost down to £2,000–£7,000. Suddenly the gap is much smaller - and in some cases, a heat pump costs barely more than a gas boiler upfront.
The catch: not every home qualifies. You need a valid EPC (Energy Performance Certificate), and properties with an EPC rating of F or G may need insulation upgrades first. The grant is also first-come, first-served and has been extended to March 2028.
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Running cost comparison over 10 years
Here's where it gets interesting. We've worked out the total cost over 10 years for a typical 3-bed semi-detached house, including installation, running costs, and maintenance.
| Cost factor | Gas boiler | Heat pump (with BUS) |
|---|---|---|
| Installation | £2,000 | £4,500 |
| Annual running cost | £850–£1,100 | £600–£900 |
| Annual service | £80–£120 | £100–£200 |
| 10-year running total | £8,500–£11,000 | £6,000–£9,000 |
| 10-year maintenance | £800–£1,200 | £1,000–£2,000 |
| Likely repair (years 5–10) | £300–£800 | £200–£500 |
| 10-year total | £11,600–£15,000 | £11,700–£16,000 |
Based on 2026 energy prices under the Ofgem energy price cap: gas at 6.8p/kWh, electricity at 24.5p/kWh. Heat pump COP of 3.0 assumed. Well-insulated 3-bed semi with 12,000 kWh annual heating demand.
The numbers are remarkably close. A heat pump edges it for a well-insulated home with the BUS grant. Without the grant, gas is still cheaper over 10 years for most properties.
When an air source heat pump makes sense
- Your home is well insulated (EPC C or above). Heat pumps run at lower temperatures than gas boilers, so they need a well-insulated house to work efficiently.
- You have (or plan to get) solar panels. Free daytime electricity dramatically cuts heat pump running costs. With a battery, even more so.
- You're on an off-peak electricity tariff. Octopus Go, Economy 7, or similar tariffs can cut heat pump running costs by 30–50%.
- You're building a new home or doing a major renovation. It's much cheaper to install a heat pump during construction when you can design the system from scratch.
- You want to future-proof. Gas prices have been volatile. Electricity prices are falling as more renewable generation comes online. The long-term trend favours heat pumps.
When a gas boiler still wins
- Your home is poorly insulated and you can't (or won't) upgrade. A heat pump in a draughty Victorian terrace will struggle - and cost more to run than gas.
- You don't have space for an outdoor unit. Air source heat pumps need an external unit roughly the size of a washing machine. If you have no suitable outside wall or garden space, it's a non-starter.
- Your radiators are small. Heat pumps work best with larger radiators or underfloor heating. If your house has small, old radiators, you may need to replace them - adding £2,000–£4,000 to the project.
- Budget is tight. Even with the BUS grant, a heat pump costs more upfront. If you need heating sorted for the lowest possible outlay, a combi boiler is still the cheapest option.
- You're in a flat or maisonette. Heat pump installation in flats is complicated - you need freeholder consent, exterior space, and potentially planning permission.
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Hybrid heat pump and gas boiler systems
There's a middle ground that rarely gets mentioned: hybrid systems. These pair a small air source heat pump with a gas boiler. The heat pump handles the bulk of your heating when it's mild outside, and the gas boiler kicks in during cold snaps.
A hybrid system costs £5,000–£10,000 installed. It works in older, less insulated homes where a heat pump alone would struggle. And it reduces your gas usage by 50–70% without the upheaval of a full heat pump installation.
The downside: hybrid systems don't qualify for the £7,500 BUS grant (only standalone heat pumps do). But they're worth considering if your house isn't heat-pump-ready and you want to reduce your carbon footprint without breaking the bank.
What about hydrogen boilers?
You might have heard that hydrogen will replace natural gas in the UK grid. The government trialled hydrogen heating in Ellesmere Port, but the results have been mixed.
The honest assessment: hydrogen-ready boilers exist, but a national hydrogen grid is unlikely before 2035 at the earliest - and many experts doubt it will happen at all for home heating. The Energy Saving Trusthas a useful guide on heat pump performance if you want to dig deeper into the numbers. Don't base today's decision on hydrogen. Buy what makes sense now.
Frequently asked questions
Is a heat pump cheaper to run than a gas boiler?
It depends on your electricity tariff and home insulation. At standard 2026 UK energy prices, an efficient heat pump costs roughly the same to run as a gas boiler for a well-insulated home. If you have solar panels or an off-peak tariff, a heat pump is significantly cheaper. In a poorly insulated house, a gas boiler currently costs less to run.
How much does a heat pump cost to install in the UK?
An air source heat pump costs £8,000–£14,000 installed before the £7,500 Boiler Upgrade Scheme grant. After the grant, you're looking at £2,000–£7,000. A ground source heat pump costs £15,000–£35,000 before any grant.
Will gas boilers be banned in the UK?
The Future Homes Standard will prevent new-build homes from installing gas boilers, with full implementation expected from 2026. For existing homes, there is no ban on gas boilers. You can still replace your gas boiler with a new gas boiler for the foreseeable future.
Do heat pumps work in cold weather?
Yes. Modern air source heat pumps work efficiently down to -15°C. They're widely used in Scandinavia where winters are far colder than the UK. Performance drops slightly in extreme cold, but UK winters rarely test them.
Compare the costs for your home
Use our cost guides and calculators to see real prices for heat pumps and boilers in your area.
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