Best Air Source Heat Pumps in the UK
When looking to buy the best air source heat pump, brands including Daikin, LG, Mitsubishi Electric, Samsung, Vaillant and Viessmann are leading the pack.
From excellent energy efficiency to all round seasonal performance, the best heat pumps give homeowners everything they need to achieve thermal efficiency, not to mention eco-friendliness for their property.
To help you choose the best air source heat pump, the WhatPrice team has analysed real customer reviews of the standout ASHP brands and models available in the UK.
Best air source heat pumps in the UK for 2025
Since a heat pump will be responsible for the thermal comfort of your home, choosing an ASHP brand and model should not be done on a whim.
While various heat pump grants exist, ASHPs remain more expensive than a traditional boiler. Likewise, the difference in how your heating and hot water are provided compared with a boiler makes it even more important to feel confident in your purchase decision.
To help you narrow down the main contenders, we’ve researched the best air source heat pump models available.
Best overall – The Daikin Altherma 3
The Daikin Altherma 3 is widely regarded as one of the best heat pumps currently available on the market.
As a high temperature heat pump, it delivers water temperatures of up to 70°C. This offers excellent compatibility with older properties along with existing radiator systems, meaning you don’t need to undertake extensive property renovations to have it installed.
For colder climates, the Daikin Altherma 3 can perform effectively in outdoor temperatures as low as -28°C. A SCOP score of 4.5 has also been achieved with this heat pump, denoting fantastic energy efficiency.
Loud noise isn’t a concern with the Daikin Altherma 3 either, with reported noise levels of just 35 dB, making it one of the quietest heat pumps to exist. For residential areas especially, this remarkably quiet operation is especially desirable.
The dedicated Daikin Onecta app also gives users full control over their heating and hot water, including through remote monitoring via smartphones or tablets.
Best budget-friendly option – Samsung EHS Mono R32
Air source heat pumps tend to have a high purchase cost, but this is not the case with the Samsung EHS Mono R32.
While the cost of this ASHP may be reduced, its impressive features certainly are not. In particular, it boasts a typical SCOP rating of 4.3 to 4.5. Plus, the unit itself is both compact and quiet.
This heat pump integrates with SmartThings to provide additional user controls.
For budget-conscious homeowners or property developers, the Samsung EHS Mono R32 ensures a low carbon heating system quite literally doesn’t have to cost the Earth.
Best for large homes – Mitsubishi Electric Ecodan R32 Zubadan
It’s a simple fact that larger properties require a more powerful heat pump. Thankfully, even the highest heating and hot water demands are not a challenge for the Mitsubishi Electric Ecodan R32 Zubadan.
Specifically, this ASHP is available in models of up to 14kW, making it geared towards large or detached homes.
Ecodan R32 Zubadan users also appreciate the ability to scale or adapt the heat pump, so that it caters towards different zones within the home. This zoned heating functionality is also fully controllable via the MELCloud app or third-party integrations.
The Mitsubishi Electric Ecodan R32 Zubadan boasts ultra quiet operation and a SCOP rating of up to 4.45.
Additional features to note include hybrid functionality for integration with conventional boilers, coastal protection mode and built-in energy tracking capabilities.
Best for small homes – Viessmann Vitocal 200-A
When space is at a premium, one of the best heat pumps for small homes is the Viessmann Vitocal 200-A.
This ASHP has been specifically designed to offer quiet operation, which can be especially important if you live in a terraced home or a flat, as close proximity to your neighbours means certain noise restrictions exist.
Another aspect that makes the Viessmann Vitocal 200-A great for smaller properties is the optional integrated cylinder which can also work to save space.
As you’d expect from Viessmann, the build quality is also excellent, with all of its features easy to control via the ViCare app.
Best eco-friendly model – Vaillant aroTHERM Plus (R-290)
Compared with powering your home with fossil fuels like gas or oil, it’s certainly the case that all heat pumps help to reduce the carbon emissions produced by your heating and hot water demands. That said, some air source heat pumps are in a league of their own, with the Vaillant aroTHERM plus a shining example here.
It is the first Vaillant heat pump to use the natural refrigerant R290, meaning it has a very low global warming potential (GWP).
Backed by a high SCOP rating and a 75°C flow temp requiring minimal retrofit changes to your property, the Vaillant aroTHERM is a firm favourite among heat pump enthusiasts.
Plus, Vaillant as a whole is a market leader in home heating technology. Its UK-based call centre is also open 364 days a year, which can offer peace of mind if this will be your first heat pump purchase.
Top air source heat pump brands compared
As someone who is looking to purchase the best air source heat pump for their home, the good news is that there are some incredible brands to choose from.
With many familiar boiler manufacturers transitioning over to heat pumps, it may be the case that you can remain with the same brand for your new low carbon heating solution. This is especially the case with the likes of Vaillant and Viessmann, which are also considered two of the best boiler brands in the UK.
Additionally, there are some stalwart brands from the world of tech jumping into the ASHP market. In particular, the likes of Samsung and LG are bringing heaps of innovation that is worth taking note of.
| Feature | Daikin | Vaillant | Mitsubishi Electric | Samsung | LG | Viessmann |
|---|---|---|---|---|---|---|
| Flagship ASHP model | Altherma 3 (Mono/Split) | aroTHERM Plus | Ecodan Ultra Quiet | EHS Mono / ClimateHub | Therma V R32 Monobloc | Vitocal 200/252-A |
| Flow temp (max) | 70°C (High Temp) | 75°C (R-290) | 60°C | 65°C | 65°C | 70°C |
| Efficiency (SCOP) | 4.5 – 5.1 | 4.6 – 5.2 | 3.9 – 4.9 | 4.1 – 4.5 | 4.4 – 4.9 | 4.5 – 5.0 |
| Noise level (dB @ 1m) | ~35–38 dB | ~28–40 dB | ~45 dB | ~35–48 dB | ~40–45 dB | ~35–45 dB |
| Smart controls | Daikin Online Controller | sensoNET | MELCloud | SmartThings | LG ThinQ | ViCare App |
| Typical warranty | Up to 7 years (via installer) | Up to 7 years | Up to 7 years | 5-7 years | 5-7 years | 5-7 years |
| Eligible for the Boiler Upgrade Scheme | Yes | Yes | Yes | Yes | Yes | Yes |
Key features to look for in a heat pump
For homeowners who are more used to boilers, buying a heat pump is unfamiliar.
So, when you are looking to buy the best air to air heat pump for the first time, it pays to know which features matter the most.
We’ve listed the top things to check to ensure your ASHP offers excellent performance, efficiency and overall user-friendliness.
Efficiency ratings (SCOP and SPF)
The efficiency ratings which apply to air source heat pumps (SCOP and SPF) are different from other types of heating systems or appliances.
| Metric | Stands for | Based on | Typical range | Usage |
|---|---|---|---|---|
| SCOP | Seasonal Coefficient of Performance | Lab simulations (standard climate zones) | 3.0-5.5 | For product comparison under standard test conditions |
| SPF | Seasonal Performance Factor | Real-world performance | 2.5-4.0 | For actual efficiency seen in installed systems |
SCOP measures a heat pump’s efficiency over an entire heating season. It compares the amount of heat output to the electricity input under standardised conditions.
The higher the SCOP score, the more energy efficient a heat pump is.
SPF is a real-world version of SCOP. The key difference is that the SPF score has been measured over time rather than using simulated test conditions. As a result, the SPF is usually lower than SCOP to reflect real-life inefficiencies.
Considering both the SCOP and SPF rating of an air source heat pump can provide you with a broader context of its expected performance.
Noise levels
Many homeowners are concerned about how noisy heat pumps are. However, it’s good to note that the sound produced by an air source heat pump is more of a gentle hum than a distinguishable noise. That’s provided the heat pump has been installed correctly of course.
Air source heat pumps (ASHP) generate between 35 and 60 decibels. The current building standards for an ASHP is that it can generate 45dB if it is installed one metre from a neighbour’s window.
You will need to check the expected heat pump noise level before you go ahead with the installation. Depending on your property type and the planned installation location, the permitted noise levels may differ.
When collecting quotes for an air source heat pump, your installer should explain what is permissible for your property.
Smart controls and connectivity
The ability to tailor your property’s heating and hot water requirements is important, especially when investing in a more expensive system like a heat pump.
Examples of smart features available in modern ASHPs include:
Energy usage data
Remote control via app
Integration with smart meters
Integration with voice assistants like Alexa or Google Assistant
Scheduling and geofencing
Third-party controls
WiFi connectivity
With so many heat pump manufacturers also major players in the tech scene, there are some truly innovative features to look out for. Although, certain features can be brand and model specific rather than being standard for all air source heat pumps.
Warranty and support
Ensure you are left warm, but not high and dry with your heat pump by reviewing the warranty and support packages carefully.
Be wary of short warranty periods. Check the coverage carefully before choosing a heat pump brand and model. Since your heat pump will be with you for the long run, it’s essential that you can count on the support and warranty protection when needed.
High temperature vs standard models
Air source heat pumps can be classed as standard or high temperature models. This variation exists to offer more flexibility for your property type and overall usage requirements.
Choose a standard ASHP if your home is well insulated, or you’re installing underfloor heating or oversized radiators. A standard model is also a great fit if you are carrying out significant renovations to your property, meaning you want your heat pump to provide maximum energy efficiency and lower running costs.
High temperature heat pumps offer the sorts of heating and hot water temperatures you are used to with a gas boiler. Newer properties, along with older homes which have undergone significant energy improvements don’t need a high temperature heat pump. However, if your property isn’t very efficient, or you want to retain your existing radiators and pipework, then a high temperature heat pump is more suitable.
While high temperature heat pumps offer the advantage of a simpler installation, they are more expensive both to purchase and run.
Costs and savings
The WhatPrice team has researched how much air source heat pumps cost.
Beyond the cost of buying and installing an ASHP, there are also some ongoing costs to consider.
Initial purchase and installation cost
Air source heat pumps have a typical cost of between £11,000 and £16,000 based on the unit price and installation costs combined.
However, most UK homeowners won’t pay the full amount due to the various grants and incentives that exist.
Running costs and maintenance
Air source heat pumps may technically run on thin air, but they still have running costs to factor in. On average, UK homeowners pay between £800 and £1,800 per year to run a heat pump.
As you might expect, there are a few things which can impact the running cost of a heat pump.
Some aspects can be managed in advance, including ensuring your property has the required insulation levels before you go ahead. This will mean your heat pump doesn’t need to work as hard to heat your home and can help lower your bills.
Heat pumps also require an annual service. The typical cost for this is between £150 and £300 per year.
It’s also worth checking the conditions of the heat pump warranty before you go ahead, as many common issues should be covered for a set period.
Available funding and rebates
The UK government is keen to push low carbon heating alternatives including heat pumps. To incentivise homeowners to make the switch from gas, there are various schemes to take advantage of. So long as you qualify, this can dramatically reduce the cost of a heat pump.
The Boiler Upgrade Scheme (BUS) is the main type of government funding to look out for. It will offer up to £7,500 towards the cost of an air source heat pump.
Additional grants include the ECO4, and also the extension to this scheme known as the ECO4 Flex.
If you live in Scotland, Home Energy Scotland also has a mixture of grants and loans available to make green energy improvements to your property, including covering the cost of a heat pump.
Analysis of user reviews by brand
Choosing the best air to air heat pump also requires consideration of the different brands available.
The WhatPrice team has analysed various customer reviews of the top heat pump brands in the UK. Crucially, we’ve looked at aspects which have earned each brand both praise and criticism to help you make an informed purchase.
Daikin pros and cons
Daikin has been in business for over 100 years. Given air source heat pumps are a relatively new technology compared with traditional gas boilers, this longevity can offer a level of reassurance.
Daikin has many certified partners including Octopus Energy and Heatable. Furthermore, most Daikin heat pumps are MSC-certified, making them eligible for the Boiler Upgrade Scheme.
The main points that Daikin customers praise include the quality of the installation, noting that the process resulted in minimal description.
Other areas of delight include responsive customer support (with its UK headquarters based in Surrey), user-friendly technical features and generous warranty periods.
However, negative feedback about Daikin mentions customer assistance taking longer than is ideal, the heat pumps not meeting the requirements of the property and difficulty finding replacement parts to perform repairs.
Vaillant pros and cons
Given Valliant is one of the leading boiler brands in the UK, transitioning to a Vaillant air source heat pump can offer customers peace of mind. This is especially the case if you have been satisfied with the product quality and customer service of your Vaillant boiler.
We reviewed the feedback from customers who have already made the switch to a Vaillant air source heat pump.
Efficiency is one of the most important factors when buying a heat pump. For Vaillant customers, this was one of the main areas of praise, along with the quiet operation of the heat pump. Overall, customers agree that Vaillant heat pumps can easily meet the heating and hot water needs of their property.
However, customers were less enthused about the long waiting times on the phone when trying to access Vaillant support. Likewise, there have been reported instances of emails or online enquiries going unanswered.
Where customers have booked a Vaillant technician to perform a repair, there have been instances of the engineer not turning up, or customers having to reschedule the appointment.
However, it’s good to note that if you get a Vaillant air source heat pump installed, you can also choose to have any servicing or repairs performed by a local installer instead.
Mitsubishi Electric pros and cons
With a strong commercial market, Mitsubishi Electric possesses a level of prestige which is attractive for domestic installations.
Those who have had a Mitsubishi Electric air source heat pump would certainly agree, with the quality and professionalism of the company’s engineers the main focus of reviews. Some customers even found that the efficiency of their heat pump improved following a service, leading to better performance and reduced energy bills.
Likewise, interactions with Mitsubishi Electric’s customer service team have proved helpful, including the ability for technicians to provide clear instructions when providing technical help remotely.
Areas of criticism relate to Mitsubishi Electrics’ ‘3 Diamond Ecodan Heat Pump Cover’, which some customers feel does not provide the expected level of service.
However, as with any heat pump cover, carefully reviewing what’s included can help manage your expectations and avoid any disappointment.
Samsung pros and cons
Most of us are familiar with Samsung outside of heating technology, with the South Korean firm a leading manufacturer of electronic household items.
Fans of Samsung will be equally pleased that technology is a core focus of the brand’s heat pumps too. Samsung heat pumps boast compatibility with Alexa, Google and other smart tech solutions.
Crucially, this level of innovation extends to the actual features of Samsung’s heat pump range. The EHS Mono HT Quiet operates at just 35 decibels, making it one of the quietest heat pumps available. This model even continues to work in extreme cold temperatures as low as -25°C. This EHS Mono HT Quiet also received the prestigious ‘iF Product Design Award’.
Looking at Samsung air source heat pumps as a whole, and the feedback is extremely positive among users. The brand is popular for its design aesthetics, making Samsung heat pumps something which users want to proudly display rather than conceal outside of their properties.
As is the case with other air source heat pump brands we’ve compared, the quality of the installation remains a crucial factor in the overall satisfaction of a Samsung heat pump. In cases where users were dissatisfied, missing components like expansion vessels, thermostats and flow sensors were frequently mentioned.
Confusions over the warranty coverage, and instances where customers felt Samsung could do more to resolve issues are also common talking points.
LG pros and cons
In true LG style, its heat pumps offer sleek sophistication at every turn. Its leading range is the LG Therma, an air to water heat pump which combines 20% electricity with 80% outside air.
Users certainly approve of the technology, with models including the LG Therma V Monobloc S heat pump having gained Quiet Mark certification. For homeowners concerned about the noise generated by a heat pump, this would be a great option to consider.
As well as running quietly, LG heat pump customers also praise the energy efficiency, with a SCOP rating of 4.67 and an A+++ energy rating reported with the Therma V R32 Monobloc S model.
When there’s a chill in the air, the indoor temperatures and indeed overall customer feedback for LG heat pumps remain toasty, with the Monobloc S providing consistent performance throughout the seasons.
The positive feedback about LG heat pumps also includes plenty of praise for the smart controls, including Wi-Fi connectivity.
Potential considerations with LG heat pumps relate to the quality of the installation, which like any heat pump can influence the performance and overall efficiency of the system. Some users also reported high pitched noises during operation.
In some instances, customers feel LG did not take adequate responsibility for resolving issues, especially when installations were carried out by approved installers.
Viessmann pros and cons
Viessmann is also a familiar brand within the traditional boiler space. However, the German heating pioneer has increasingly invested in its heat pump technology in recent years, making Viessmann a top contender for the best air source heat pump brand.
As is the verdict with Viesmann boilers, excellent energy efficiency is the main area of praise for Viessmann air source heat pumps. Models such as the Vitocal 150-A and 200-A have exceptional feedback. Some customers report receiving 5 kWh of heat for every 1 kWh of electricity consumed, which equates to 500% efficiency.
Quiet operation is another merit of Viessmann air source heat pumps, along with the smart control and remote monitoring functionality. Overall, Viessmann is associated with reliability, with the brand having one of the highest percentages of 5 star reviews for any heat pump brand we’ve compared on TrustPilot.
However, where Viessmann could potentially improve is by making its customer support more accessible. Similar to other air source heat pump brands we’ve reviewed, long wait times on the phone have been reported.
Best air source heat pump FAQs
Do you have a question about choosing the best air source heat pump for your home? We’ve answered some of the top queries below.
To find out more about buying a heat pump for a property in the UK, head over to our heat pump guides. Here, you’ll find more details about the typical heat pump cost and more.
How do I choose the right size heat pump for my home?
Generally speaking, most homes require a heat pump size of between 3kW and 14kW.
Rest assured that your installer will select the best air source heat pump for your property in terms of size and overall capabilities.
To do so, they’ll perform a heat loss calculation which involves assessing the heat loss of each room. Your installer will consider aspects such as the floor area, ceiling height, insulation, window size, window glazing type, air leakage and the room usage as part of their calculations.
Can I install a heat pump in a flat or terraced house?
The short answer is yes, you absolutely can install a heat pump in a flat or a terraced house.
However, you will need to ensure you have both the space to accommodate a heat pump as well as any applicable permission. In particular, the required permission can differ depending on whether you live in England, Scotland or Wales.
Furthermore, if your property is leasehold, then you will need permission from the freeholder to be able to install a heat pump.
It is also important to consider the practical requirements of a heat pump. For instance, your property must have the available space to accommodate the heat pump and hot water cylinder. Also, the noise limits will need to be respected, which involves ensuring that no more than 42dB is audible from the nearest window.
Rest assured that your installer will be able to check many of these requirements on your behalf. That said, it’s still good to read up on any permissions that may apply in your specific scenario.
What is the most reliable brand of heat pump?
Daikin, LG, Mitsubishi Electric, Samsung, Vaillant and Viessmann are equally regarded as the most reliable heat pump brands available in the UK.
Naturally, each brand has something different to offer within its heat pump product line. However, in terms of aspects such as energy efficiency, features, installer feedback and customer satisfaction, these brands are a class above the rest.
Which air source heat pump is the most efficient?
What constitutes an efficient heat pump can look slightly different depending on the size of your home and overall needs.
The Viessmann Vitocal is widely considered the best overall heat pump for efficiency, including when installed in smaller properties.
However, other notable mentions include the Panasonic Aquarea L for smaller properties, Vaillant aroTHERM for achieving high temperatures, the Daikin Altherma 3H HT for colder regions and the Hitachi Yutaki for providing exceptional power.
We recommend asking a trusted heat pump installer for advice on which brand and model would offer the best efficiency for your property. Remember, the insulation quality of your home will also impact efficiency levels, so ensure you take care of any required energy efficiency updates first.
How do I find a trusted installer?
To ensure you receive the best air source heat pump installation experience, it’s key to choose the installer carefully.
Selecting an installer who is on the Microgeneration Certification Scheme (MCS) is highly recommended. If you will be receiving a government grant towards the cost of a new heat pump, MCS certification is also a requirement.
The installer should hold relevant qualifications such as the Level 3 Award in the Installation and Maintenance of Heat Pump Systems (Non-Refrigerant Circuits).
Beyond this, take your time to read reviews on platforms such as Checkatrade, TrustPilot and Yell. Also, if you know anyone who has had a good heat pump installation experience, this can also help to identify trusted traders in your area.
Ensure to collect a minimum of 2-3 quotes so that you can think about your decision before you go ahead.