Most people can’t imagine another way of heating their homes besides the traditional gas boiler. But there are a few new options in town like the air source heat pump, with promises of saving you money, being more efficient and generally providing greener energy to make the planet more sustainable.
But how do these promising heat sources stack up? In this particular battle, we pit the gas boiler off against the air source heat pump.
Which Has the Longer Life?
The average heat pump can last at least 15 years, but there are reports that modern heat pumps can last for as much as 25 years.
The long lifespan is thought to be down to their rigid design. As there are only a small number of moving parts, there’s not much that can get damaged.
Comparatively, most LPG or gas boilers last just 7 to 12 years usually.
The heat pump wins this one quite handily
Which Heat Source is More Efficient?
Efficiency in heating systems equates to the volume of the energy they supply that is converted into heat energy. Traditional boilers are thought to have 50 to 75% efficiency, meaning around ⅓ to ¼ of the supplied energy to the boiler is wasted.
However, biomass boilers and modern oil, LPG and gas boilers (which we also install) have higher efficiency at around or more than the 90% mark.
That being said, heat pumps still have higher efficiency reaching up to 350%, with a coefficiency of performance measuring 3.5.
Heat pumps can achieve such high numbers because they absorb heat that is found naturally outside and brings it inside.
It’s looking good for the air source pumps so far…
Which Costs Less Upfront?
A gas boiler is probably your best option, if you are looking for the cheapest and quickest choice. According to Energy Saving Trust, a gas boiler replacement will cost £2,300 on average.
However, depending on if you are connected to the mains gas supply or not (and other factors), the cost of either a ground source or air source heat pump can range from £8,000 all the way up to £30,000. This depends on the property, the build solution required and other factors.
The difference is that you can claim most back through grants like the Renewable Heat Incentive. You are also able to gain an RHI income free from tax if you opt for a biomass boiler, which will initially cost between £8,000 and £15,000 (sometimes more).
Considering the longevity of a heat pump in relation to cost, in the life of one you may replace a boiler twice over the same period of time.
The air source pump will work out cheaper long-term and you can claim much of the initial cost back through a grant but the gas boiler is cheaper up front. What’s best for you depends on your priorities, whether long-term or short-term.
The traditional boiler gets its first points on the board
Which Takes Up Less Space?
An air source style heat pump features an outdoor fan unit that uses the same space as a conventional washing machine.
Although not always, it is connected to a hydrobox or indoor heat exchanger, which is the size of a conventional boiler. The hydrobox is then connected to a hot water cylinder, similarly to a gas boiler.
A ground source-style heat pump takes up as much as twice the amount of floor space in your property where there needs to be trenches dug where the long pipes of the system can be laid.

Not only is this a large area of land and is quite a long installation.
However, once the installation is complete, and the concrete has been laid or shrubbery has regrown, it will be barely noticable.
The actual heat pump part is placed in your property and can be as small as a large shoebox or as big as a normal boiler.
Modern boiler designs or combination boilers don’t need to use hot water cylinders, as they heat water directly as it comes from the mains supply. They are only designed for use in flats and smaller properties.
If you take into consideration the amount of outdoor space you need, the worst option is a ground source-style heat pump. Whereas if you are only considering how much space they need in your property, a biomass boiler is likely to take up the most.
They are bigger than conventional gas boilers, though the size of these special heating systems will depend on the heat demand and size of your property.
This is one of those “it depends” type of answers, so one may win in some households, while the other wins in another. Call us and find out which would be best for you.
Which Requires the Least Maintenance?
It is recommended that you arrange for maintenance checks annually for heat pumps, but it is not a requirement. They can extend the lifespan and preserve the efficiency, but there won’t be any serious issues if you skip them.
However, boilers need maintenance checks annually at the very least. As these can protect you against carbon monoxide poisoning risks. But also, old boilers love to play up when they haven’t been used in a while, and at the worst times! Hint: it’s not in the Summer…
The air source heat pumps come out with the win on this one
Which Has Lower Running Costs?
Although electricity is 4 times more expensive than LPG, oil and gas, the costs required to run these systems are all similar. What does this mean?
If electricity costs are reduced, heat pumps running costs would be much less than traditional boilers and heating methods. Based on the energy market and how volatile it is, this is likely to happen eventually.
This is, though, at best, speculative. There is no way of knowing with any certainty when the prices might decrease or increase.
However, as more hydroelectricity plants, wind farms and solar farms are appearing around the country, there is a good indication that electricity prices will drop.
Even with the higher electricity prices, most people will instantly get a sharp decline in their energy bill. Again, this all depends on individual circumstance and our installers would be happy to advise.
This one comes out a draw
Which Has the Most Extra Costs?
Although most boiler replacements only take a few days to complete, there are often additional costs involved. With heat pump installations, there are a few important requirements that your property needs to meet for them to function efficiently.
For instance, it needs to be insulated properly for the ideal low flow temperature and it may be that you need to install larger radiators. If you find this is the case, we would recommend you install underfloor heating.
While it is expensive, underfloor heating installed across a large surface area provides the lower flow temperature which equates to lower electricity bills.
Another great bonus is that your rooms will warm quicker than they would if you relied only on radiators.
Overall though, the gas boiler is generally “plug and play”. The air source pump can be, but usually needs optimal conditions to do its best work. Installers can advise you on whether you might need these or not and give you tips of maximising your pump
The boiler nicks this one

Which is the Most Eco-Friendly?
There is one clear winner when you look at the heating options from an eco-friendly point of view. Although modern LPG, oil and gas boilers offer over 90% efficiency, as heat pumps do not use any fossil fuels, they are the best.
The fact that they offer such high efficiency means that even if they use electricity derived from a coal-fired power generator, the volume of carbon emissions they’d generate would be minimal.
You can also opt to have heat pumps powered by green electricity such as wind or solar farms, which can reduce carbon emissions generated to zero or close enough.
The other incredibly green heating option is biomass boilers. By burning wood, they only emit the same carbon emissions that were originally absorbed, so they could be seen as being carbon-neutral.
Besides the biomass boilers, the air pump heat source wins this one by a country mile
Which Offers the Best Experience For Users?
The user experience of both heat pumps and gas boilers will depend on the model you choose as modern systems are fully automatic.
You will find, as is the case with the majority of modern home appliances, there are various extras to consider that improve the control, comfort and how easy they are to operate.
Some of these are worth considering, including programmable room thermostats, timers and app-controlled systems.
This is where one of the main disadvantages lies with a biomass style boiler. They require more effort on your part to get them working as you need to fill them up with the wood pellets.
Aside from this though, you’re going to get similar automation options with either.
This round is a draw with both options being good
Summary: Air source heat pump or traditional gas boilers?
Unfortunately, if you were looking for one that stands out from the crowd as being the best, even after considering all the points above, we can’t really point you in the direction of one that stands head and shoulders above the other.
It may sound like a cop-out, but in our experience, the answer is almost always “it depends” on your location, property, environment and many other factors. We supply and fit both options with many happy customers.
A heat pump is our recommendation if you are not connected to the mains gas supply, are constructing a sustainable property, want generally cheaper bills with less maintenance, or just want to have a more eco-friendly life.
Whereas, if you are still connected to the mains gas supply and don’t want to switch, it’s probably in your best interests economically to simply replace your current gas boiler with a modern and higher efficiency model gas boiler.
To find out how much a heat pump or energy efficient boiler might cost you, fill out the home suitability survey we have supplied or call us today on 0333 577 2555.
FAQs
Are gas boilers better than heat pumps? ›
Most top gas boilers are usually 90-94% efficient, which means that some heat will always be lost and emitted from their flue pipes. On the other hand, heat pumps are around 300-400% efficient. Thus, you will get 3 to 4 times more heat for every kilowatt (kW) of electricity the heat pump uses.
What is the most eco-friendly gas boiler? ›Water Tube Boilers. For many companies looking for an energy-efficient, eco-friendly boiler, the modular water tube boiler made by Miura is the best option all around. For starters, modular water tube boilers require a lot less water to operate than conventional boilers due to their unique design.
Are heat pumps green energy? ›Heat pumps are a considerably greener technology than gas heat, but they may be more expensive to operate than gas heat. Heat pumps are much more efficient than window air conditioners.
What is the best form of eco heating? ›The greenest option for eco heating systems is either a water source heat pump (which takes heat from a large body of water) with a heat battery, or a ground source heat pump. These pumps operate with equal efficiency night and day.
Which is cheaper to run gas boiler or air source heat pump? ›Conclusion. If a heat pump is installed in a thermally efficient property, properly, they'll likely be cheaper to run than a gas boiler.
Should I replace my gas boiler with a heat pump? ›Heat pumps provide longer-term financial benefits because you will likely see a reduction in your heating bills due to increased energy savings. Heat pumps also have a longer life expectancy of between 10-15 years whereas condensing boilers have an average life expectancy of around seven years.
What is the green alternative to a gas boiler? ›Solar thermal panels are worth considering as a gas boiler alternative. These eco-friendly systems absorb heat from the sun in solar collectors, which are fitted to your roof. The heated fluid is then transferred to your hot water tank, where it's ready to use.
Are gas boilers being phased out in 2025? ›The government has announced that by 2025, all new homes will be banned from installing gas and oil boilers and will instead be heated by low-carbon alternatives.
How green are air source heat pumps? ›Low Carbon Footprint
For every 3 to 4 units of energy produced from an air source heat pump, only 1 unit of electricity is used, making it a far better alternative to cut emissions.
Installing heat pumps would avoid $600 million in health damages and $1.7 billion in climate damages each year. It would also directly save homeowners money on energy costs. They also found that for all homes, assuming moderate electric grid decarbonization, heat pump use cut greenhouse gas emissions.
Are heat pumps more environmentally friendly? ›
A heat pump is definitely better for the environment. Heat pumps use only about a third as much electricity as baseboard electric heaters and considerably less energy than gas or oil furnaces. You don't need gas or oil to operate a heat pump, as it relies only on electricity.
What is the most eco friendly heating and cooling system? ›According to the Environmental Protection Agency, geothermal heat pumps are the number one most energy efficient, eco-friendly, and inexpensive heating and cooling systems in existence.
Which form of heating is 100% energy-efficient? ›Electric resistance heating is 100% energy efficient in the sense that all the incoming electric energy is converted to heat.
What is the most efficient eco friendly energy source? ›Wind comes out on top by a wide margin over all the other sources. It is followed in order by geothermal, hydro, nuclear and solar.
Why are gas boilers being phased out? ›And now, as part of the Heat and Buildings Strategy, next on the agenda is tackling emissions from homes and businesses – and the phasing out of boilers powered by natural gas is a big part of that. It's all about achieving that goal of net zero.
Can air source heat pump replace gas boiler? ›Can the heat pump replace your gas or oil boiler ? In many cases, yes, a heat pump can provide all the heating and hot water you need for your home.
Why is my air source heat pump so expensive to run? ›Heat Demand
The more energy you need, the bigger your heat pump, and the higher the cost of running the system due to increased use of electricity over time.
No, Gas boilers will not be banned from 2025. It is likely however, that new build properties from 2025 will not achieve the 75% - 80% carbon reduction targets they have been given with a gas-fired boiler.
What is the downside of heat pumps? ›Air source heat pumps can experience issues such as icing in cold temperatures, which can ultimately damage the system. Although modern heat pumps do often have automatic defrosting. Their efficiency will also be lower at very cold temperatures, and use more electricity during those cold days.
When should you use a boiler vs heat pump? ›It is generally accepted that a ground source heat pump is better suited to larger properties, while either an air source heat pump or ground source heat pump is suitable for properties under around 300m2. Boilers are better suited to producing rapid heat in older, less efficient buildings.
What will replace gas boilers in 2023? ›
Gas boilers are expected to be replaced by low-carbon heating systems, such as air source heat pumps. Now, heat pumps are more expensive than gas boilers.
What will replace gas boilers in 2035? ›Boris Johnson has confirmed that all gas boiler installations will be banned across the UK by 2035, leading the way for all new heating systems to replace them. The new heating systems will use low carbon technologies, such as electric heat pumps, or support promising new technologies like hydrogen-ready boilers.
Are electric boilers greener than gas? ›Also, unlike gas, oil, or LPG, an electric boiler does not produce carbon emissions when working so are seen by many as a more environmentally friendly choice. Electric boilers can be installed to produce hot water for both your heating system and domestic hot water.
Will hydrogen replace gas boilers? ›New boilers will be built to a new 'hydrogen-ready' standard, which means they'll work with natural gas but can also be easily modified to run on 100% hydrogen. According to some industry estimates, these boilers should be available from 2023-2025.
What is more efficient than a gas boiler? ›While electric boilers are more efficient and waste less fuel than gas boilers, they are rather expensive to run. This is because of the high prices of electricity across the UK. Heating your house with an electric boiler will likely cause your energy bills to go up.
Should I replace my 20 year old gas boiler? ›You should consider replacing your boiler after around 10 to 15 years as this is when a boiler becomes less efficient, and you may lose heat and money. If your boiler is within its early teenage years, now is the time to upgrade to a new more energy-efficient boiler.
What happens to my gas boiler after 2025? ›In 2025, gas boilers will be replaced by renewable heating systems in all new-build homes. This is part of a government effort to achieve net-zero CO2 emissions by 2050.
Are gas boilers more efficient than 10 years ago? ›Overall, modern boilers are far more efficient than even 10 years ago. Today, the most modern best combi boiler options are condensing systems and so we'll be looking at these systems today and explaining this further for you.
Are gas boilers going to be phased out? ›No, Gas boilers will not be banned from 2025. It is likely however, that new build properties from 2025 will not achieve the 75% - 80% carbon reduction targets they have been given with a gas-fired boiler.
Why are boilers used instead of heat pumps? ›Energy efficient homes
When comparing traditional gas boilers and heat pumps, it has been found that most boilers have an expected efficiency of around 50%-75%. This means that in the process of providing heat for your home, between a quarter and a half of that energy is wasted.