Is an air source heat pump better than a gas boiler? For most UK homes, the honest answer is yes on efficiency, carbon and lifespan, and no on upfront cost and simplicity. A heat pump turns each unit of electricity into around three units of heat, while even a new gas boiler wastes about 15 percent of the gas it burns. That efficiency gap is real and it is large. But a heat pump costs roughly three times as much to install, needs a suitable home to work well, and can cost slightly more to run on a standard electricity tariff. This guide works through every comparison that matters, with the October 2026 prices, so you can judge the verdict for your own home rather than taking a sales pitch on trust.

Is a Heat Pump Better Than a Gas Boiler? The Short Answer

An air source heat pump is better than a gas boiler if you care about efficiency, carbon emissions and how long the system lasts. It is worse if you want the cheapest installation, the simplest setup, or instant hot water from a combi boiler. On running costs the two are close, and the winner depends on your tariff. If your home is well insulated, has space for an outdoor unit and a hot water cylinder, and you plan to stay for a decade or more, the heat pump is the better buy. If your home is draughty, your budget is tight, or you will move within a few years, a new gas boiler is still the sensible choice. The rest of this guide shows the working behind that verdict.

How Each System Heats Your Home

A gas boiler burns natural gas in a flame and passes the heat into water that circulates through radiators. A modern condensing boiler recovers some heat from its own exhaust gases, which is why the best new models reach around 90 percent efficiency in laboratory tests. In real homes the Energy Saving Trust puts a typical new gas boiler at about 85 percent efficiency, and an older boiler due for replacement at more like 75 percent. The other 15 to 25 percent of the gas you pay for leaves as waste heat.

An air source heat pump works the other way round. It does not create heat by burning fuel. It collects warmth from the outside air, even on a cold day, and uses a compressor to raise that warmth to a temperature useful for radiators and hot water. Because it moves heat rather than making it, one unit of electricity can deliver three or more units of heat. The Energy Saving Trust says heat pumps tend to run with a seasonal performance factor, or SPF, of about 3.1, and that a good quality installation managed well can reach an SPF above 4. That is the single most important number in this whole comparison, and it explains why heat pumps win on efficiency by a wide margin.

Efficiency: The Heat Pump’s Biggest Win

Efficiency is where the contest is least close. A gas boiler can never beat 100 percent efficiency, because it turns fuel into heat and some always escapes. A heat pump routinely delivers 300 percent or more, because it is moving heat that already exists in the air. Put the two side by side at the Energy Saving Trust’s typical figures, and the heat pump delivers each unit of heat using roughly a quarter of the energy a gas boiler needs.

That matters twice over. First, it means the heat pump uses far less energy for the same warm home. Second, it is the reason heat pumps can compete on running costs even though electricity costs far more per unit than gas. The catch is that the efficiency advantage only survives if the system is designed and installed properly. A heat pump fitted with undersized radiators, poor pipework insulation or wrong controls will run at a much lower SPF, and the Energy Saving Trust warns that the most common heat pump problems come from installation quality, not from the equipment itself. Get three quotes from MCS certified installers, and treat the cheapest quote with suspicion if it skips radiator upgrades.

Running Costs: Closer Than the Efficiency Gap Suggests

Here is where the heat pump’s big efficiency win meets an awkward fact: electricity costs about three times as much as gas. Under the Ofgem price cap from 1 October to 31 December 2026, electricity averages 26.32 pence per kilowatt hour and gas averages 7.97 pence, both for Direct Debit customers in England, Scotland and Wales. The typical dual fuel bill under the same cap is 1,723 pounds a year. So the heat pump’s threefold efficiency advantage is almost exactly cancelled by the threefold price gap, which is why the two systems cost a similar amount to run.

The maths makes this precise. A heat pump running at an SPF of 3.1 produces each kilowatt hour of heat for 26.32 divided by 3.1, which is 8.49 pence. A new gas boiler at 85 percent efficiency produces each kilowatt hour of heat for 7.97 divided by 0.85, which is 9.38 pence. On those figures the heat pump is cheaper per unit of heat, but only just. The break even point is an SPF of 2.81: any heat pump running above that beats a new gas boiler on running costs, and any running below it loses. The Energy Saving Trust’s typical SPF of 3.1 clears that bar, but not by a huge margin.

Take a home that needs 12,000 kilowatt hours of heat a year, a typical figure for a three bedroom semi. The gas boiler needs 14,118 kilowatt hours of gas to deliver it, costing 1,125.18 pounds a year at the capped rate. The heat pump needs 3,871 kilowatt hours of electricity, costing 1,018.84 pounds. The saving is about 106 pounds a year. That is a real saving, but it is not the dramatic cut some installers promise, and it depends on the heat pump actually achieving an SPF of 3.1 in your home.

Your tariff changes the answer more than anything else. The Energy Saving Trust is clear: on standard electricity tariffs, where electricity costs nearly four times as much as gas, a heat pump can cost slightly more to run than a new gas boiler. Switch to a heat pump time of use tariff, which charges less when demand is low, and the same heat pump can cost less than a gas boiler. The Trust’s research also finds that heat pumps paired with solar panels, a battery and a smart tariff can cut bills significantly, with some of the shortest payback periods of any combination. And if you disconnect the gas supply altogether once the heat pump is in, you stop paying the gas standing charge of 29.68 pence a day, or about 108 pounds a year, which is a saving a boiler can never offer. For the full worked comparison, see our guide to whether it is cheaper to run a gas boiler or a heat pump.

Upfront Cost and Grants

Upfront cost is the gas boiler’s clearest win. The Energy Saving Trust puts the typical cost of installing an air source heat pump at around 12,000 pounds, and the price varies with the size of the unit, the size of the property, and whether radiators need upgrading. A straightforward like for like combi boiler replacement typically costs 2,000 to 4,000 pounds. Even after the Boiler Upgrade Scheme grant, the heat pump costs more: the scheme pays 7,500 pounds towards an air source or ground source heat pump in England and Wales, which brings a typical installation down to around 4,500 pounds out of pocket, still above a new boiler.

Two deadlines matter here. Homes off the gas grid that currently heat with oil or LPG can claim 9,000 pounds instead of 7,500, but only until 31 March 2027. And the 0 percent VAT rate on heat pump installations also ends on 31 March 2027, returning to 5 percent from 1 April 2027. Waiting past March therefore costs an oil heated home around 2,000 pounds more for the same system. Full details are in our guides to the Boiler Upgrade Scheme 9,000 pound grant and when 0 percent VAT on heat pumps ends.

The honest way to judge the upfront gap is over the life of the system, not on day one. A heat pump that saves around 106 pounds a year on running costs and lasts 20 years or more will not repay a 4,500 pound net installation cost on bill savings alone. The case for a heat pump rests on the grant, the carbon saving and the longer life, not on a quick payback. Anyone promising a three year payback on a heat pump in a gas heated home is selling, not advising.

Carbon: The Clearest Win for the Heat Pump

Carbon is the comparison with the widest margin. A gas boiler burns fossil fuel in your home, so every kilowatt hour of heat comes with carbon dioxide attached. A heat pump runs on electricity, and the UK grid keeps getting cleaner, so its emissions fall every year without you changing anything.

The Energy Saving Trust calculates that an average three bedroom home saves around 1,900 kilograms of carbon dioxide a year by switching from a new gas boiler to a heat pump, and around 2,900 kilograms a year when replacing an old gas boiler. British Gas, using its own Carbon Cruncher tool, puts the saving for an average home at around 1,404 kilograms a year. The exact number depends on your home’s size and how much heat you use, but every estimate points the same way: a heat pump cuts heating emissions by roughly half to two thirds. The Energy Saving Trust makes the same point in EPC terms: switching to a heat pump will always improve your home’s environmental rating dramatically, even if the headline EPC rating, which is based on running costs, stays roughly the same.

This is also the comparison that improves with time. A gas boiler installed today will burn gas at the same carbon intensity for its whole life. A heat pump installed today gets cleaner every year as more wind and solar join the grid. If you care about the carbon footprint of your home, this is the section that decides the question.

Lifespan and Maintenance

A heat pump should outlast a gas boiler by a clear margin. The Energy Saving Trust says a heat pump is likely to last 20 years or more, longer than the average gas or oil boiler. Most gas boilers are replaced after 10 to 15 years, which means a household could buy and fit two boilers in the lifetime of one heat pump. That changes the lifetime cost comparison in the heat pump’s favour, and it is the part of the maths most often left out of running cost only breakdowns.

Maintenance is a smaller difference. Both systems need an annual service. The Energy Saving Trust says a heat pump service typically costs around 150 pounds a year and covers an electrical safety check, thermostat operation, cleaning filters and coils, and checking the compressor, fan and pump. A gas boiler service typically costs around 80 to 120 pounds a year. So the heat pump costs a little more to service each year, but you service it for twice as many years before replacing the unit. Neither system is maintenance free, and both need a competent engineer once a year.

Comfort, Hot Water and How Your Home Feels

A heat pump heats your home differently, and you will notice. Gas boilers run radiators hot, typically at flow temperatures of 65 to 75 degrees, so rooms warm up quickly and radiators feel hot to the touch. Heat pumps run at lower flow temperatures, around 35 to 55 degrees, which is more efficient but means radiators feel cooler and rooms take longer to warm up. That is why installers often fit larger radiators: more surface area makes up for the lower temperature.

The practical adjustment is to run a heat pump steadily rather than in bursts. The Energy Saving Trust advises keeping the heating at a steady level, setting controls to come on earlier in the morning, and not worrying if the radiators do not feel all that hot, because they will still heat the room if left on for long enough. Homes with underfloor heating suit heat pumps best, because the large floor area works well at low flow temperatures. Homes with small radiators and poor insulation are the hardest fit, and may need radiator upgrades to stay comfortable.

Hot water is the other everyday difference. A combi gas boiler heats water on demand, so there is no cylinder and no waiting. A heat pump heats water stored in a cylinder, and it stores that water at a lower temperature than a boiler would, so the cylinder needs to be slightly bigger to fill a bath or run a shower. The system also runs a sterilisation cycle that periodically heats the cylinder above 60 degrees to prevent bacterial growth. If you have a combi boiler today, switching to a heat pump means finding space for a cylinder, which is a real constraint in small homes and flats.

Noise and Neighbours

A gas boiler sits indoors and is almost silent. A heat pump has an outdoor unit with a fan, and it makes a low hum. Most modern air source heat pumps produce between 40 and 50 decibels measured one metre from the outdoor unit, which is about the level of a quiet conversation or a refrigerator. Whether that bothers your neighbours depends on where the unit sits and how close their windows are.

The planning rules are specific. In England, an air source heat pump installed under permitted development must pass the MCS 020 noise calculation, which caps the predicted sound level at 42 decibels at your nearest neighbour’s habitable room window. Your MCS certified installer must complete and sign off that assessment. If the calculation fails, which is more likely in a terrace with close set windows, you need a full planning application with a noise impact statement. The rules were relaxed in 2025: the old requirement to site the unit at least one metre from a boundary was removed in England, and the permitted size limit rose from 0.6 to 1.5 cubic metres, with detached houses now allowed two units under permitted development instead of one. Most domestic installations still go ahead without planning permission, but check the noise assessment before you commit, not after.

Space, Radiators and Insulation

A heat pump asks more of your home than a boiler does. It needs an outdoor unit with clear airflow around it, space indoors for a hot water cylinder, and usually larger radiators or underfloor heating. It also works best in a well insulated home. The Energy Saving Trust advises improving insulation before or alongside a heat pump installation where that is realistic, and notes that financial support is available, including through the Great British Insulation Scheme.

That does not mean a heat pump cannot work in an older or poorly insulated home. The Trust is clear that the installer should design the system to match your expected heating needs, and that a poorly insulated home will likely need bigger radiators throughout, and possibly an extra one here and there. But the worse the insulation, the lower the SPF, the higher the running costs, and the weaker the case for switching. Insulation first, heat pump second, is the right order for most homes. A gas boiler, by contrast, will heat a draughty home without complaint, because it can simply burn more gas and run its radiators hotter.

What the Future Holds for Gas Boilers

The direction of policy is unmistakable, even though there is no ban on gas boilers in existing homes. The Future Homes Standard, published on 24 March 2026, comes into force on 24 March 2027. From that date, new homes in England must be built with low carbon heating such as heat pumps or heat networks, and must emit at least 75 percent less carbon than homes built to 2013 standards. Gas boilers cannot meet those targets, so in practice new homes built under the standard will not have gas boilers. A 12 month transitional period runs for projects already in the pipeline.

What the standard does not do is touch existing homes. There is no requirement to remove or replace a working gas boiler, and the government has set no date for phasing out new gas boilers in existing homes. The previously proposed 2035 phase out has been dropped and does not appear in the government’s Warm Homes Plan, published in March 2026. So if you fit a new gas boiler today, nobody will force you to take it out. But you will be fitting the last generation of a technology that new homes have already moved beyond, and you should expect gas prices, carbon policy and the second hand market to keep moving against it over the boiler’s life.

When a Gas Boiler Still Wins

There are homes where a gas boiler is still the right answer, and it is worth naming them plainly. If your home is poorly insulated and you cannot improve it, a heat pump will run at a low SPF and cost more to run than the brochure promises. If you have no outdoor space for a unit, or no space indoors for a cylinder, a heat pump may not fit at all. If you live in a flat, permitted development does not apply and planning permission is much harder. If you plan to move within five years, you are unlikely to recover the upfront cost or enjoy the longer lifespan. And if your budget only stretches to a boiler, a new efficient boiler is a genuine improvement on an old one: at 85 percent efficiency against 75 percent, it cuts gas use by roughly a tenth overnight.

The gas boiler also wins on simplicity. It is a familiar technology, every heating engineer understands it, parts are cheap and available, and it slots into the pipework and radiators you already have. A heat pump is a bigger project with more ways to go wrong, and its performance depends heavily on the quality of the design and installation. That is a real risk, and it is the main reason to choose your installer as carefully as your equipment.

The Verdict

So, is an air source heat pump better than a gas boiler? On the measures that matter most over the long term, yes. It is roughly three times as efficient, it cuts heating carbon by about half to two thirds, and it should last around twice as long. On the measures that matter on day one, no: it costs about three times as much to install before grants, it needs space and suitable radiators, and it changes how your home feels. Running costs are close enough that your tariff matters more than your technology.

	Air source heat pump	Gas boiler
Efficiency	SPF around 3.1, good installs above 4	Around 85 percent new, 75 percent old
Typical install cost	Around 12,000 pounds, around 4,500 after the 7,500 pound grant	2,000 to 4,000 pounds
Running cost per kWh of heat	8.49 pence at SPF 3.1 and October 2026 prices	9.38 pence at 85 percent efficiency
Annual running cost, 12,000 kWh of heat	About 1,019 pounds	About 1,125 pounds
Carbon saving	About 1,900 kg CO2 a year vs a new boiler, 2,900 kg vs an old one	Baseline
Lifespan	20 years or more	10 to 15 years
Annual service	Around 150 pounds	Around 80 to 120 pounds
Hot water	Stored in a cylinder, lower temperature	Instant from a combi, no cylinder
Noise	40 to 50 dB at one metre, 42 dB limit at neighbour’s window	Almost silent, indoors
Future proofing	Standard for new homes from March 2027	No ban on existing homes, but no phase out date either

Choose the heat pump if your home is reasonably insulated, you have space for the outdoor unit and a cylinder, you plan to stay for ten years or more, and you can switch to a heat pump tariff. Choose the gas boiler if your budget is tight, your home is hard to insulate, you have no space for a cylinder, or you will move soon. Either way, get the insulation right first, get three MCS certified quotes, and check the grant deadlines before March 2027. That is the real answer to the question, is an air source heat pump better than a gas boiler? It is better for the right home, and the wrong choice for the wrong one.

Frequently Asked Questions

Is an air source heat pump better than a gas boiler?

Yes, on efficiency, carbon and lifespan. A heat pump delivers around three units of heat for each unit of electricity, cuts heating carbon by roughly half to two thirds, and should last 20 years or more against 10 to 15 for a gas boiler. But it costs more to install, needs space and suitable radiators, and can cost slightly more to run on a standard tariff. The better choice depends on your home, your budget and how long you plan to stay.

Is a heat pump cheaper to run than a gas boiler?

At October 2026 price cap rates, a heat pump at the Energy Saving Trust’s typical SPF of 3.1 costs about 8.49 pence per kilowatt hour of heat, against 9.38 pence for a new gas boiler, a saving of about 106 pounds a year on a typical home. On a standard electricity tariff a heat pump can cost slightly more than a new gas boiler, while on a heat pump time of use tariff it can cost less. Disconnecting the gas supply saves the gas standing charge of about 108 pounds a year on top.

How long does an air source heat pump last compared to a gas boiler?

The Energy Saving Trust says a heat pump is likely to last 20 years or more, longer than the average gas or oil boiler. Most gas boilers are replaced after 10 to 15 years, so a household could fit two boilers in the lifetime of one heat pump. Both systems need an annual service, typically around 150 pounds for a heat pump and 80 to 120 pounds for a gas boiler.

Will a heat pump keep my house as warm as a gas boiler?

Yes, if the system is designed properly, but it heats differently. Heat pumps run radiators at lower flow temperatures, around 35 to 55 degrees against 65 to 75 for a boiler, so rooms warm up more slowly and radiators feel cooler. Larger radiators or underfloor heating make up the difference, and the system works best run steadily rather than in bursts. Poorly insulated homes may need radiator upgrades to stay comfortable.

Do heat pumps make a lot of noise?

Most modern air source heat pumps produce between 40 and 50 decibels measured one metre from the outdoor unit, about the level of a quiet conversation. Under permitted development rules in England, the MCS 020 noise calculation must show no more than 42 decibels at your nearest neighbour’s habitable room window. If the calculation fails, you need a full planning application.

Will gas boilers be banned?

There is no ban on gas boilers in existing homes, and the government has set no date for phasing them out. The Future Homes Standard, in force from 24 March 2027, means new homes in England must use low carbon heating such as heat pumps, so new builds will effectively stop getting gas boilers. You can still repair or replace a gas boiler in an existing home.

Sources

• Ofgem, Energy price cap unit rates and standing charges, 1 October to 31 December 2026. https://www.ofgem.gov.uk/your-energy-supply/your-energy-bill/energy-price-cap-unit-rates-and-standing-charges
• Energy Saving Trust, Air source heat pumps: costs, savings and benefits. https://energysavingtrust.org.uk/advice/air-source-heat-pumps
• Energy Saving Trust, Your heat pump questions answered by our experts. https://energysavingtrust.org.uk/heat-pump-questions-answered
• GOV.UK, Apply for the Boiler Upgrade Scheme. https://www.gov.uk/apply-boiler-upgrade-scheme
• GOV.UK, VAT on energy saving materials and heating equipment, Notice 708/6. https://www.gov.uk/guidance/vat-on-energy-saving-materials-and-heating-equipment-notice-7086
• British Gas Carbon Cruncher findings, as reported by The Eco Experts. https://www.theecoexperts.co.uk/heat-pumps/carbon-savings
• Energy Saving Trust carbon saving figures, as reported by Renewable Energy Hub. https://www.renewableenergyhub.co.uk/main/heat-pumps-information/co2-carbon-savings-of-a-heat-pump-and-their-environmental-cost
• Future Homes Standard, GOV.UK Building Circular 01/2026, in force 24 March 2027, as reported by Skills Training Group and Home Energy Model. https://www.skillstg.co.uk/blog/gas-boilers-to-be-banned-by-2025/ and https://home-energy-model.co.uk/news/2026-03-24-future-homes-standard-published/
• MCS 020 noise standard and permitted development rules, as reported by Checkatrade and UK Heat Pump Guide. https://www.checkatrade.com/blog/expert-advice/are-air-source-heat-pumps-noisy/ and https://ukheatpumpguide.co.uk/blog/heat-pump-noise-neighbours/