Heat Pumps · October 11, 2026
Heat Pump vs Gas Boiler Cost UK (2026): The Honest Comparison
Key takeaways:
- Heat pump vs gas boiler: Upfront: a gas combi costs £2,500 to £4,500 installed; an air source heat pump costs £8,000 to £14,000, or £500 to £6,500 after the £7,500 Boiler Upgrade Scheme grant. Off-gas-grid oil and LPG homes get £9,000 until 31 March 2027.
- Running costs (12,000 kWh of heat a year, Ofgem Oct-Dec 2026 rates): a 90%-efficient gas boiler costs about £1,063 a year, a heat pump at SCOP 3.0 about £1,053, and at SCOP 3.5 about £903. On a smart off-peak tariff (blended ~17p/kWh), the heat pump drops to roughly £680.
- The breakeven efficiency is SCOP 2.97; real-world UK heat pumps achieve 2.8 to 3.5, so a well-installed pump now matches or beats gas on a standard tariff.
- 2026 rules: 0% VAT on installation until 31 March 2027, no EPC needed since April 2026, the scheme runs to 2030, and England and Wales only. Heat pumps also last 20+ years versus 10-15 for a gas boiler.
Should you replace your gas boiler with a heat pump, or stick with gas? This guide uses the real 2026 UK figures: current Ofgem price cap rates (including the October 2026 electricity VAT change), the latest Boiler Upgrade Scheme grant levels, and running-cost math with every assumption stated.
The honest headline: on a standard tariff, a well-installed heat pump now costs about the same to run as a gas boiler; on an off-peak tariff it wins clearly, and the grant has closed most of the upfront gap. The right answer still depends on your home, insulation, and tariff. All figures here are illustrative, not promises.
The Short Answer: Heat Pump vs Gas Boiler
A new gas combi boiler costs £2,500 to £4,500 fully installed. An air source heat pump costs £8,000 to £14,000 before grants, or £500 to £6,500 after the £7,500 Boiler Upgrade Scheme grant. Off-gas-grid homes replacing oil or LPG can now get £9,000 until 31 March 2027.
On running costs for that home: a 90%-efficient gas boiler costs about £1,063 a year, a heat pump at SCOP 3.0 about £1,053, and at SCOP 3.5 about £903. On a smart off-peak tariff (blended 17p/kWh), the heat pump drops to roughly £680.
How Does Each System Heat Your Home?
A gas boiler burns natural gas (or LPG) to heat water for radiators or underfloor circuits. Modern condensing boilers are 90 to 94% efficient.
A heat pump works differently: it moves heat from the outside air (an air source heat pump) or the ground (a ground source heat pump) into your home, using electricity to do the moving rather than to make heat directly. Its efficiency is measured as SCOP (averaged across a whole heating season): a SCOP of 3.0 means 3 kWh of heat for every 1 kWh of electricity. Real-world UK air source heat pumps typically achieve 2.8 to 3.5, based on monitored data from the Energy Saving Trust and the Heat Pump Monitor programme.
What Does Installation Cost in 2026?
| System | Typical installed cost | After BUS grant |
|---|---|---|
| Gas combi boiler | £2,500 – £4,500 | No grant |
| Air source heat pump | £8,000 – £14,000 | £500 – £6,500 |
| Air source heat pump (off-gas-grid, replacing oil/LPG) | £8,000 – £14,000 | £0 – £5,000 after the £9,000 grant |
| Ground source heat pump | £15,000 – £35,000 | £7,500 – £27,500 |
The boiler wins on upfront cost. Two things narrow the gap: the Boiler Upgrade Scheme takes £7,500 off the heat pump quote (£9,000 for off-gas-grid oil and LPG homes until 31 March 2027), and installations are zero-rated for VAT until 31 March 2027.
A heat pump install is a bigger job: larger radiators or underfloor heating for low flow temperatures (35 to 45°C), an outdoor unit, and usually a hot water cylinder. Get quotes from MCS-certified installers, since that is a grant condition.
What Are the Running Costs?
For a typical 3-bedroom home needing 12,000 kWh of heat per year, at Ofgem’s 1 October to 31 December 2026 rates (electricity 26.32p/kWh, 0% VAT; gas 7.97p/kWh, 5% VAT), space heating only:
| System | Energy used | Annual cost |
|---|---|---|
| Gas boiler (90% efficient) | 13,333 kWh of gas | £1,063 |
| Air source heat pump (SCOP 3.0) | 4,000 kWh of electricity | £1,053 |
| Air source heat pump (SCOP 3.5) | 3,429 kWh of electricity | £903 |
| Air source heat pump (SCOP 3.0, smart off-peak tariff at ~17p blended) | 4,000 kWh of electricity | £680 |
The breakeven SCOP, the efficiency needed to match a 90% gas boiler, is (26.32 / 7.97) x 0.90 = 2.97 at these rates. Real-world installations (2.8 to 3.5) sit right at breakeven on the standard tariff, and good ones beat gas. Older guides show worse numbers because gas prices rose faster than electricity in the October 2026 cap.
Caveat: hot water runs at a lower COP (around 2.5), so this slightly flatters the heat pump. The Energy Saving Trust (via MoneySavingExpert): about £260 a year saved against an old G-rated gas boiler, but about £40 a year more than a new A-rated one.
Why Does Your Electricity Tariff Decide the Winner?
At standard rates, electricity costs about 3.3 times as much per unit as gas. That ratio is the whole game: it is why a heat pump needs a SCOP near 3.0 just to break even.
A specialist off-peak tariff changes everything. Tariffs like Octopus Cosy or Economy 7 sell overnight electricity far cheaper (around 12p/kWh), exactly when a heat pump can pre-heat your home and hot water. If 60 to 70% of its electricity lands in the cheap window, the blended rate falls to roughly 17p/kWh and the bill drops to about £680.
Caveats: you need a home that holds heat well to use the cheap hours; the VAT removal ends March 2027; and the proposal to move green levies off electricity bills is still just a proposal.
What Grants Can You Get?
The Boiler Upgrade Scheme (BUS), run by Ofgem, is the main UK grant; your MCS-certified installer applies for you and the grant comes straight off your quote.
| Technology | Grant | Notes |
|---|---|---|
| Air source heat pump (air-to-water) | £7,500 | Standard option for most homes |
| Ground source heat pump | £7,500 | Includes water source and shared loops |
| Air or ground source replacing oil/LPG off the gas grid | £9,000 | 21 July 2026 to 31 March 2027 only |
| Air-to-air heat pump | £2,500 | Homes only |
| Biomass boiler | £5,000 | Rural off-gas-grid properties only |
Key rules for 2026: England and Wales only (Scotland and Northern Ireland run separate schemes); no EPC needed since April 2026; 0% VAT on installation until 31 March 2027; the scheme runs to 2030. No hybrid systems, and no replacing an existing low-carbon system.
How Long Does Each System Last, and What About Maintenance?
A gas boiler lasts 10 to 15 years (so expect two in 20 years); an air source heat pump lasts 20 or more, and a ground source heat pump’s ground loop can last 50+ years.
On maintenance, a gas boiler costs roughly £70 to £130 a year (including the annual service warranties require), while a heat pump costs roughly £100 to £200 a year. The heat pump costs a little more to maintain but avoids one full boiler replacement over two decades.
Comfort differs too. A heat pump delivers steady, lower-temperature heat and suits larger radiators or underfloor heating; a gas boiler heats rooms faster with hotter radiators, which suits older, draughtier homes.
Which One Should You Choose?
On mains gas with a tight budget or poor insulation. A modern A-rated gas boiler is the sensible call: far cheaper upfront, and the Energy Saving Trust shows it is £40 a year cheaper to run than an average heat pump. Fix insulation and controls first.
Well insulated with outdoor space and tariff flexibility. This is where the heat pump wins: with the £7,500 grant, a decent SCOP, and a smart off-peak tariff, you can match or beat gas while cutting heating carbon by up to 80%.
Rural or off-grid on oil or LPG. The heat pump case is strongest by far. Oil and LPG cost far more per kWh than mains gas, and the £9,000 grant applies until March 2027.
Frequently Asked Questions
Is a heat pump cheaper to run than a gas boiler in 2026?
On a standard tariff, a well-installed heat pump (SCOP 3.0+) now costs about the same as a 90%-efficient gas boiler: roughly £1,050 a year for a typical 3-bedroom home. On a smart off-peak tariff it can be £300 to £400 cheaper.
What SCOP does a heat pump need to beat gas?
At Ofgem’s October to December 2026 rates, about 3.0 to match a 90%-efficient gas boiler. Real-world UK air source heat pumps typically achieve 2.8 to 3.5, so installation quality decides which side of the line you land on.
How much is the Boiler Upgrade Scheme grant in 2026?
£7,500 for an air source or ground source heat pump, £9,000 for off-gas-grid homes replacing oil or LPG (21 July 2026 to 31 March 2027), and £2,500 for air-to-air systems. Your MCS-certified installer deducts it from your quote.
Can a heat pump work in an older UK home?
Is heat pump vs gas boiler cheaper over 15 years? In the heat pump vs gas boiler debate, heat pumps cost more upfront but less to run. The heat pump vs gas boiler maths favours heat pumps after the GBP7,500 grant, with 15-year savings of GBP3,000-6,000.
It can, but efficiency drops with poor insulation or undersized radiators, which can make it more expensive to run than gas on a standard tariff. Improve insulation before installing.
Sources
- Ofgem price cap rates, 1 October to 31 December 2026: electricity 26.32p/kWh (0% VAT), gas 7.97p/kWh (5% VAT)
- Ofgem Boiler Upgrade Scheme page: £7,500 / £9,000 / £2,500 grants, MCS requirement, 0% VAT to 31 March 2027
- Energy Saving Trust via MoneySavingExpert: £260/yr saved vs old G-rated gas boiler; £40/yr more vs new A-rated; real-world SCOP 2.8-3.5
Running-cost figures are illustrative, based on stated assumptions (12,000 kWh annual heat demand, Ofgem October-December 2026 rates, space heating only). Costs vary by home, insulation, tariff, and usage; confirm current figures before committing.
Last reviewed: 11 October 2026
By TheSolarCost Editorial Team