Heat Pump vs Gas Boiler UK 2026: The Honest Cost Comparison
At current energy prices, heat pumps and gas boilers cost almost exactly the same to run. But the full picture — grants, lifespan, tariffs and future-proofing — tells a different story.
The heat pump vs gas boiler decision is one of the most significant home energy choices UK homeowners face in 2026.
The heat pump vs boiler debate has been running for years. In 2026, with energy prices stabilised, the £7,500 Boiler Upgrade Scheme in full swing and a maturing installer market, the numbers are finally clear enough to give an honest answer.
The short answer: at current Ofgem price cap rates, a well-installed heat pump and a modern gas boiler cost almost the same to run — within £30–£150 per year of each other. The decision comes down to upfront cost, the £7,500 grant, your insulation, your energy tariff, and how long you plan to stay.
Here's the full breakdown — with real 2026 numbers, not marketing claims. For the wider picture on grants, types and whether it's worth it at all, see our complete Heat Pumps UK guide.
Want to see how the maths works for your home? Use our free heat pump running cost calculator to compare your current heating costs against a heat pump based on your actual energy usage.
The Key Numbers: 2026 Energy Prices
Everything in this comparison starts with the current October 2026 Ofgem price cap rates:
Electricity costs roughly 3.3× more per unit than gas. For a heat pump to match a gas boiler on running costs, it needs to deliver 3.3 units of heat for every 1 unit of electricity — a COP of 3.3. This is the number everything else hinges on, and it's a genuinely easier bar to clear than it was a year ago.
Running Cost Comparison — A Typical 3-Bed Home
For a typical 3-bedroom semi-detached UK home with 12,000 kWh annual heat demand:
⚠️ The SCOP question is everything. The median UK heat pump installation achieves a SCOP of around 2.8–3.1 — meaning average installations cost slightly more to run than a gas boiler. Well-designed installations in well-insulated homes regularly hit SCOP 3.5–4.0. This is why installation quality and home insulation matter so much — they determine which row of the table above you end up in.
The Smart Tariff Game-Changer
The table above uses the standard electricity rate of 26.32p/kWh. Switch to a dedicated heat pump tariff and the economics shift dramatically:
-
Octopus Intelligent Go7p/kWh overnight — runs heating and hot water during cheap hours~£300–£350/yr heatingvs ~£1,040 on standard tariff
-
Octopus CosyCheap electricity across three windows spread through the day — designed specifically for heat pumpsSaves £200–£350/yrvs standard tariff
-
Agile OctopusBest with solar + battery — charge cheap on the lowest half-hours, discharge at peakSaves £300–£500/yrsolar + battery + heat pump
A heat pump on Octopus Intelligent Go at 7p/kWh with a SCOP of 2.8 delivers heat at 2.5p/kWh — comfortably cheaper than gas at 8.7p/kWh. Switching tariff is free and takes 10 minutes. It's the single most impactful thing a heat pump owner can do. See our full Octopus tariff comparison for the detail on each option.
A modern air source heat pump can be installed on most UK homes in 2–3 days with no major structural work required.
Upfront Heat Pump vs Gas Boiler UK Cost Comparison
The grant changes everything. A 3-bed semi heat pump installation that costs £13,000 before grant becomes £5,500 after — comparable to a premium boiler replacement. The heat pump then lasts 20–25 years versus 12–15 for a boiler, and you avoid replacing the boiler a second time during that period. See our full heat pump cost breakdown for property-size-specific figures.
20-Year Total Cost of Ownership
Over 20 years, factoring in installation, running costs and likely boiler replacement at year 13:
🔥 Gas Boiler (20 years)
- Installation (x2)£7,000
- Running costs (20yr)£20,800
- Servicing£2,400
- Total~£30,200
♨️ Heat Pump (20 years)
- Installation (after grant)£5,500
- Running costs (20yr)£22,500
- Servicing£2,800
- Total~£30,800
On a standard tariff, the totals are genuinely close over 20 years — within a few hundred pounds either way, depending on installation quality and SCOP achieved. Switch to a smart tariff and the heat pump pulls clearly ahead. Energy Saving Trust data suggests a 20-year saving of approximately £3,900 when smart tariffs are factored in.
When a Heat Pump Clearly Wins
✅ Replacing oil or LPG
Oil and LPG cost considerably more per kWh than gas. A heat pump at SCOP 3.0 on standard electricity is already competitive, and dramatically better on off-peak. Plus the £9,000 grant for oil/LPG homes from July 2026. The financial case is compelling.
✅ Well-insulated home
EPC C or above, good loft and cavity wall insulation. The heat pump runs at higher SCOP because it doesn't need to work as hard to maintain temperature. These installations consistently hit SCOP 3.5+ and beat gas on running costs. See our insulation guide if you're not there yet.
✅ Willing to switch to smart tariff
Octopus Intelligent Go at 7p/kWh makes a heat pump at SCOP 2.8 cheaper than gas on any metric. Switching tariff is free. It's the single biggest lever available to heat pump owners.
✅ Have or planning solar panels
Running a heat pump on solar surplus brings effective electricity cost to near zero during peak generation months. Combined with a home battery, the savings are substantial year-round — see our full battery comparison for real installed prices and which brands work best alongside a heat pump.
When a Gas Boiler Still Makes Sense
- →Poor insulation — EPC D or below with no insulation planned. A heat pump in a draughty home will underperform and cost more. Fix insulation first — then reconsider.
- →Planning to move within 5 years — the financial case improves over longer timeframes. Short-term, the upfront cost differential (even with the grant) may not pay back before you sell.
- →Boiler still under 5 years old — replacing a working boiler mid-life doesn't make financial sense. Wait until replacement is due then switch.
- →Flat with no outdoor space — air source heat pumps need an outdoor unit. Ground source requires land. Neither works in most flats.
Beyond Running Costs — The Bigger Picture
Running costs tell only part of the story. Three factors increasingly favour heat pumps beyond the pure numbers:
-
1
Future gas price risk
Gas prices have historically been more volatile than electricity. The 2021–2022 energy crisis saw gas prices spike 400%. A heat pump insulates you from this risk entirely. -
2
EPC ratings and property value
Planned EPC reforms are expected to increasingly favour low-carbon heating over time. A gas boiler in a rental property may become a liability. A heat pump adds value and future-proofs EPC compliance. -
3
Carbon emissions
The UK grid is getting greener every year. A heat pump running on today's grid already produces roughly 50–60% less carbon than a gas boiler. By 2030 the advantage will be significantly greater as renewable generation increases.
Switching to a smart tariff is the single most impactful thing a heat pump owner can do — saving £200–£500 per year with no hardware changes.
The Honest Verdict
In 2026, the heat pump vs gas boiler decision is closer than the headlines suggest. For most UK homeowners with a suitable home, the case stacks up — particularly once you factor in the grant, the smart tariff opportunity, and the 20-year lifespan advantage.
It's not a slam dunk on day-to-day running costs at current prices. But it's a reasonable financial decision for most homeowners — and a much stronger one if you're replacing oil or LPG, have good insulation, or are willing to switch to an off-peak tariff.
The worst decision you can make is to install a heat pump in a poorly insulated home without switching tariff, using an inexperienced installer. Get a full heat loss survey from an MCS-certified installer, compare at least 3 quotes, and run the numbers for your specific home before committing. For the complete picture on types, grants and whether a heat pump is worth it for your situation, see our Heat Pumps UK guide.
See what a heat pump would cost and save for your home
Use our free heat pump running cost calculator to compare your current heating costs against a heat pump — adjusted for your home size, insulation and tariff.
Use the Free Calculator →Related Guides
Published June 2026, updated September 2026. Running cost figures based on the October 2026 Ofgem price cap (electricity 26.32p/kWh, gas 7.97p/kWh). All figures are estimates for a typical 3-bedroom semi-detached home with 12,000 kWh annual heat demand and are intended as illustrations only. Actual costs depend on your specific property, insulation, system design, installer and tariff. Always obtain a full heat loss survey from an MCS-certified installer before making a decision. Cool Power Co is an independent comparison service and is not affiliated with any manufacturer, installer or energy supplier.
Get Free Heat Pump Quotes
Compare up to 4 quotes from MCS-certified local installers. The £7,500 BUS grant is applied directly to your invoice. Free, no obligation.
Get My Free Quotes →✅ Free · ✅ No obligation · ✅ MCS certified installers only