Heat Pump vs Gas Boiler — Running Costs, Efficiency & Which Is Better (2026)
An honest look at whether switching from gas to a heat pump makes financial sense for your home
Key Takeaways
- Heat pump running costs are £850-£1,100/year at standard rates vs £750-£1,000/year for gas, but £500-£650/year on heat pump tariffs
- An air source heat pump costs £8,000-£18,000 before the grant, £500-£10,500 after
- The £7,500 BUS grant closes the gap on upfront cost significantly
- Heat pumps are 300-400% efficient (COP 3-4) vs 92-94% for gas boilers
- Over 10 years, a heat pump with the grant costs roughly the same or less than gas
The heat pump vs gas boiler debate has shifted quite a bit over the past couple of years. Gas prices spiked, came back down, and settled at a level that still makes heating expensive. Meanwhile, heat pump technology has improved, installation costs have dropped, and the government has bumped the BUS grant to £7,500. So are heat pumps worth it in 2026? For many homes, yes — but not for everyone, and the answer depends on your property, your budget, and how long you plan to stay.
This guide puts real numbers on the heat pump vs gas boiler comparison. No vague promises about "saving the planet" — just a straight look at what each system costs to buy, install, and run, so you can decide what actually makes sense for your household.
How Heat Pumps and Gas Boilers Work
Before getting into costs, it helps to understand why these two systems are so different in how they produce heat.
A gas boiler burns natural gas to heat water, which is then pumped through radiators or underfloor heating. Modern condensing boilers capture some of the waste heat from flue gases, reaching around 92-94% efficiency. That means for every £1 of gas you burn, about 93p turns into useful heat.
An air source heat pump works more like a fridge in reverse. It absorbs heat from the outside air — even when it's cold — and compresses it to a higher temperature using electricity. The heated refrigerant then warms your water and radiators. Because the pump is moving heat rather than creating it, it delivers 3 to 4 units of heat for every 1 unit of electricity used. That's a coefficient of performance (COP) of 3-4, or 300-400% efficiency.
This difference in how they work is why the air source heat pump vs gas boiler running cost comparison isn't just about the price of gas versus electricity. The heat pump's efficiency multiplier changes the maths entirely.
Running Costs Compared
Heat pump running costs depend on three things: the price of electricity, the system's efficiency (COP), and how much heat your home needs. Let's work through the numbers with current UK energy prices.
The calculation
Under the Q2 2026 Ofgem price cap, gas costs around 6p per kWh and electricity around 28p per kWh. A typical UK home uses about 12,000 kWh of heat per year. Here's what that costs with each system:
Cost Per kWh of Heat Delivered
- Gas boiler (93% efficient): 6p ÷ 0.93 = 6.5p per kWh of heat
- Air source heat pump (COP 3.5): 28p ÷ 3.5 = 8.0p per kWh of heat
At standard electricity rates, gas is currently a little cheaper per unit of heat than a heat pump at COP 3.5. But the picture shifts dramatically with dedicated heat pump tariffs (15-18p/kWh electricity), which bring heat pump running costs well below gas. And at COP 4.0 — which many modern units achieve in mild UK weather — the gap narrows even at standard rates.
| System | Fuel Cost | Efficiency | Cost Per kWh Heat | Annual Cost (12,000 kWh) |
|---|---|---|---|---|
| Gas boiler | 6p/kWh | 93% | 6.5p | £750-£1,000 |
| Air source heat pump (COP 3.0) | 28p/kWh | 300% | 9.3p | £1,000-£1,250 |
| Air source heat pump (COP 3.5) | 28p/kWh | 350% | 8.0p | £850-£1,100 |
| Air source heat pump (COP 4.0) | 28p/kWh | 400% | 7.0p | £750-£950 |
The range in annual costs reflects different home sizes and insulation levels. A well-insulated 3-bed semi will be at the lower end; a draughty 4-bed detached at the higher end.
Here's the key detail: some energy suppliers now offer specific heat pump tariffs with lower electricity rates (around 15-18p/kWh). On those tariffs, a COP 3.5 heat pump delivers heat for just 4.3-5.1p per kWh — running costs drop to around £500-£650 per year, roughly half the cost of gas heating. If you're considering whether are heat pumps worth it, these tariffs tip the scales heavily in their favour. Adding solar panels makes the economics even stronger.
Installation Costs
This is where the heat pump vs gas boiler comparison gets uncomfortable. Heat pumps cost significantly more to install, even with the BUS grant. Here's what you're looking at:
| System | Cost Before Grant | BUS Grant | Cost After Grant |
|---|---|---|---|
| Gas boiler replacement | £2,500-£4,000 | None | £2,500-£4,000 |
| Air source heat pump | £8,000-£18,000 | £7,500 | £500-£10,500 |
| Ground source heat pump | £15,000-£35,000 | £7,500 | £7,500-£27,500 |
That's a big range for air source heat pumps, so let's break it down. A straightforward installation in a well-insulated home with suitable radiators might come in at £8,000-£12,000 before the grant. After the £7,500 BUS grant, you're paying £500-£4,500 — which puts it in the same ballpark as a new gas boiler.
Costs climb when your home needs extra work: bigger radiators, upgraded pipework, a hot water cylinder (if you currently have a combi boiler), or improved insulation. These additions push the total towards the £14,000-£18,000 end before the grant.
What drives up air source heat pump vs gas boiler installation costs?
- Radiator upgrades — heat pumps run at lower temperatures, so some radiators may need upsizing (£150-£400 per radiator)
- Hot water cylinder — if switching from a combi boiler, you'll need one installed (£800-£1,500)
- Pipework modifications — larger bore pipes may be needed (£500-£2,000)
- Insulation improvements — recommended before installing a heat pump (varies widely)
- Electrical supply upgrade — some homes need a larger fuse or three-phase supply (£500-£2,000)
10-Year Total Cost of Ownership
Upfront cost is only part of the picture. When you factor in running costs, maintenance, and the BUS grant over a 10-year period, the gap narrows or disappears entirely.
| Cost | Gas Boiler | ASHP (With Grant) | ASHP (No Grant) |
|---|---|---|---|
| Installation | £3,000 | £4,500 | £12,000 |
| Running costs (10 years) | £8,500 | £6,000 | £6,000 |
| Annual maintenance (10 years) | £1,500 | £1,500 | £1,500 |
| 10-year total | £13,000 | £12,000 | £19,500 |
With the BUS grant and a heat pump electricity tariff, a heat pump actually costs less than gas over 10 years. Without the grant, the heat pump costs around £6,500 more over the decade. That's why the grant is so important to the "are heat pumps worth it" question — it makes the economics work for most households right now.
Beyond 10 years, the heat pump pulls ahead. Gas boilers typically last 12-15 years and need replacing; a heat pump lasts 20-25 years. Over 20 years, you'd buy one heat pump but two gas boilers. That second boiler purchase (£3,000-£4,000) plus higher cumulative running costs tips the long-term comparison firmly in the heat pump's favour.
Efficiency: Heat Pump vs Gas Boiler
Efficiency is where heat pumps really stand apart. The numbers speak for themselves.
| Metric | Gas Boiler | Air Source Heat Pump |
|---|---|---|
| Efficiency rating | 92-94% (ErP A-rated) | 300-400% (COP 3.0-4.0) |
| Energy input for 12,000 kWh heat | 12,900 kWh gas | 3,000-4,000 kWh electricity |
| Best performance | Consistent year-round | Highest in spring/autumn |
| Worst performance | Consistent year-round | Cold snaps (COP drops to 2.0-2.5) |
| Hot water efficiency | 90-94% | 250-300% (COP 2.5-3.0) |
A gas boiler can never exceed 100% efficiency — it's burning fuel and some energy always escapes. A heat pump regularly exceeds 300% because it's harvesting free energy from the air. Even in the depths of January, when outdoor temperatures hover around 2-5°C, a decent air source heat pump maintains a COP of 2.5-3.0.
The seasonal COP (SCOP) is the number that matters most — it's the average efficiency across a full year, accounting for cold snaps and milder periods. Most air source heat pumps installed in UK homes achieve a SCOP of 2.8-3.5, depending on the system and how well the home is insulated.
The Boiler Upgrade Scheme (BUS) Grant
The BUS grant is the single biggest factor in whether are heat pumps worth it for your household. It knocks £7,500 off the installation cost, and your installer handles the application.
BUS Grant at a Glance
- Amount: £7,500 for air source or ground source heat pumps
- Where: England and Wales only
- Deadline: Scheme runs until March 2028
- Who applies: Your MCS-certified installer applies on your behalf
- Payment: Deducted from your invoice — you never handle the money
Eligibility requirements
- You must be replacing a fossil fuel heating system (gas, oil, LPG, electric, or coal)
- Your property must have a valid EPC (the insulation recommendation requirement was dropped in 2024)
- The heat pump must be installed by an MCS-certified installer
- One grant per property — you can't claim again if you've already received one
In Scotland, the Home Energy Scotland grant offers up to £7,500 plus an optional interest-free loan of up to £7,500. Northern Ireland has separate schemes. If you're outside England and Wales, check your local government's website for current offers.
When a Heat Pump Makes Sense
Not every home is equally suited to a heat pump. These are the situations where the air source heat pump vs gas boiler comparison comes down clearly in favour of the heat pump:
Well-insulated homes. If your walls, loft, and floors are properly insulated, a heat pump works brilliantly. Lower heat demand means the system runs less, costs less, and achieves a higher COP. EPC rating C or above is the sweet spot.
Off-gas-grid properties. If you're currently heating with oil, LPG, or electric storage heaters, a heat pump is almost certainly cheaper to run. Oil heating costs around 8-10p per kWh of heat; a heat pump delivers heat for 6-7p. The savings are immediate.
New builds. Building regulations now favour heat pumps for new homes. The house is designed around the system from the start, with proper insulation, underfloor heating, and correctly sized radiators. This is where heat pumps perform at their best.
Homes with space for a cylinder. If you already have or can fit a hot water cylinder, the switch is simpler. If you're on a combi boiler, you'll need to find space for one, which adds cost and complexity.
People planning to stay long-term. The financial case for a heat pump gets stronger every year you live in the house. If you're staying 10+ years, the lower running costs compound nicely. Are heat pumps worth it if you're moving in 3 years? Probably not.
When a Gas Boiler Is Still the Better Choice
Heat pumps aren't right for every home or every budget. Here's when sticking with gas makes more sense:
Poorly insulated homes without budget to fix it. A heat pump in a draughty house has to work harder, runs less efficiently, and costs more. If you can't afford insulation upgrades on top of the heat pump cost, a gas boiler replacement is the more practical choice for now.
Small radiators throughout. Older homes often have compact radiators designed for the high flow temperatures of a gas boiler (60-80°C). Heat pumps work best at 35-45°C, so those radiators might not warm the rooms properly without being swapped out. If you'd need to replace most of your radiators, the extra cost can be hard to justify.
Very tight budget. A gas boiler replacement costs £2,500-£4,000. Even with the £7,500 BUS grant, many heat pump installations still cost more upfront. If cash flow is the priority, a new gas boiler is the cheaper immediate option.
No outdoor space for the unit. An air source heat pump needs an outdoor unit roughly the size of a washing machine. If you live in a flat or terraced house with no suitable external wall or ground space, installation may not be practical.
Your current boiler still has life in it. If your gas boiler is under 10 years old and working well, replacing it now means writing off years of remaining service. It might make more sense to wait and switch when it needs replacing anyway.
Environmental Impact
If carbon footprint matters to you — and for many people it does — there's a clear winner here.
| System | CO2 per kWh of Heat | Annual CO2 (12,000 kWh home) |
|---|---|---|
| Gas boiler | 215g | 2,580 kg |
| Air source heat pump | 55-65g | 660-780 kg |
A heat pump cuts your heating carbon emissions by around 70% compared to gas. As the UK electricity grid continues to decarbonise — renewables now make up over 50% of generation — that gap will widen further. By 2030, heating your home with a heat pump could produce 80-85% fewer emissions than gas.
Gas boilers also produce nitrogen oxides (NOx) and other pollutants that affect local air quality. Heat pumps produce zero direct emissions at the point of use.
The government has confirmed that new gas boiler installations in new-build homes will be phased out. While the exact timeline has shifted, the direction is clear: heat pumps are the intended replacement for gas heating in the UK. Fitting one now future-proofs your home against tightening regulations.
Heat Pump Myths Debunked
There's a lot of misinformation about heat pumps floating around. Let's look at the most common claims and what's actually true.
"Heat pumps are too noisy"
Modern air source heat pumps operate at 40-50 dB at one metre — roughly the volume of a quiet conversation or a household fridge. Planning regulations require that the unit doesn't exceed 42 dB at the nearest neighbour's window. In practice, you'll struggle to hear it from inside your house. Older models were louder, which is where this reputation comes from.
"Heat pumps don't work when it's cold"
Modern units work down to -20°C or colder. UK winters rarely dip below -5°C. Norway, Sweden, and Finland — countries with far harsher winters — have some of the highest heat pump adoption rates in the world. Efficiency does drop in very cold weather (COP might fall to 2.0-2.5), but the system keeps running and keeps you warm.
"Heat pumps are too expensive to run"
At standard electricity rates (28p/kWh), a heat pump with COP 3.5 costs about 8.0p per kWh of heat versus 6.5p for gas — slightly more. But on a heat pump tariff (15-18p/kWh), heat costs drop to 4.3-5.1p per kWh — well under half the cost of gas. Most heat pump owners sign up for these tariffs, making their running costs significantly lower.
"You need underfloor heating"
Underfloor heating is ideal for heat pumps but not essential. Properly sized radiators work fine. A heat loss survey will tell you which radiators (if any) need upgrading. Many homes need to change just 2-3 radiators, not rip up floors.
"Heat pumps take ages to heat a house"
Heat pumps work best when they run at a steady, lower temperature rather than blasting heat in short bursts like a gas boiler. Most owners set their system to maintain a consistent temperature throughout the day. The house is always warm — you just don't get the on-off cycle you're used to with gas. Many people find this more comfortable once they adjust.
"The government will ban gas boilers soon"
No outright ban on gas boilers for existing homes has been announced. The phase-out applies to new-build homes, and even that timeline has been pushed back. You can still buy and install a gas boiler in an existing property. But with each passing year, the incentives and regulations move further toward heat pumps, so the direction of travel is clear.
Frequently Asked Questions
Are heat pumps worth it in 2026?
For most UK homeowners, yes. After the £7,500 BUS grant, a typical air source heat pump costs £500-£10,500. Heat pump running costs are similar to or lower than gas boilers, and they last 20+ years versus 12-15 for a boiler. The savings increase as gas prices rise and electricity tariffs favour heat pump users. The main exceptions are poorly insulated homes and households on very tight budgets.
Is a heat pump cheaper to run than a gas boiler?
At standard UK energy prices (gas 6p/kWh, electricity 28p/kWh), a heat pump with COP 3.5 costs about 8.0p per kWh of heat versus 6.5p for gas. However, on dedicated heat pump electricity tariffs (15-18p/kWh), running costs drop to £500-£650 per year — roughly half the cost of gas at £750-£1,000. Most heat pump owners sign up for these tariffs.
How much does a heat pump cost to install in the UK?
An air source heat pump costs £8,000-£18,000 before the BUS grant. After the £7,500 grant, you'll pay £500-£10,500 depending on your property and what extra work is needed. A straightforward installation in a well-insulated home typically comes in at the lower end. A gas boiler replacement, by comparison, costs £2,500-£4,000.
Do heat pumps work in cold weather?
Yes. Modern air source heat pumps work down to -20°C or lower. Efficiency drops in very cold weather — COP might fall to 2.0-2.5 — but UK winters rarely go below -5°C. Scandinavian countries with much harsher winters use heat pumps widely. The key is proper sizing and good insulation in your home.
What is the BUS grant for heat pumps?
The Boiler Upgrade Scheme provides £7,500 towards the cost of an air source or ground source heat pump in England and Wales. Your MCS-certified installer applies on your behalf, and the grant is deducted from your invoice. You need a valid EPC and must be replacing fossil fuel heating. The scheme runs until March 2028.
Are heat pumps noisy?
Modern heat pumps produce around 40-50 dB at one metre — about the same as a fridge or a quiet conversation. Planning rules require that noise doesn't exceed 42 dB at the nearest neighbour's window. Most homeowners say they quickly stop noticing the sound. Older models were louder, but current units are much quieter.
Do I need to upgrade my radiators for a heat pump?
Not always. Heat pumps run at lower flow temperatures (35-45°C versus 60-80°C for boilers), so undersized radiators may not heat rooms properly. A heat loss survey will identify which, if any, radiators need replacing. Many homes only need to swap 2-3 radiators rather than the whole lot. Underfloor heating works brilliantly with heat pumps but isn't required.
How long do heat pumps last?
A well-maintained air source heat pump lasts 20-25 years. Gas boilers typically last 12-15 years. Over a 20-year period, you'd likely need to replace a gas boiler once but not a heat pump, which makes the long-term cost comparison more favourable for heat pumps.
Want to see how much a heat pump would cost for your home? Use our free heat pump calculator to get an estimate. Or read our guide to the best air source heat pumps to compare specific models. Ready to get quotes? Find MCS-certified heat pump installers near you.
Find Heat Pump Installers Near You
Compare MCS-certified heat pump installers in your area. All can apply for the £7,500 BUS grant on your behalf.