Best Air Source Heat Pumps in the UK (2026)
The best air source heat pump is the one that suits your home and is designed well by your installer. Here are the 13 brands with a strong UK presence, compared on the figures that matter: rated seasonal efficiency (SCOP), installed price, warranty and who each one suits.
Therma V R290 Monobloc 12kW: SCOP 5.33 at 35°C, 3.86 at 55°C (MCS)
8 years as standard, before any extended cover
All 13 brands compared
| Brand | Best for | SCOP 35°C / 55°C | Sound power | Warranty | Installed, before grant |
|---|---|---|---|---|---|
| LG Therma V | Homeowners who want a quiet R290 monobloc with strong cold-weather output from a major electronics brand | 5.33 / 3.86 | 49 dB(A) | 3 yr (up to 7) | Price on quote |
| Ideal Logic Air UK brand | Households who want a UK-built heat pump from a familiar boiler brand, installed through Ideal's installer network | 5.09 / 3.63 | 55 dB(A) | Not published | Price on quote |
| Grant Aerona3 | Off-gas homes replacing oil or LPG heating, where the £9,000 grant can apply in England and Wales | 5.2 / 3.47 | 64 dB(A) | 1 yr (up to 7) | £8,000 to £13,000 |
| Vaillant aroTHERM plus | Efficiency-first buyers who want a proven, widely monitored unit | 4.88 / 3.63 | 55 dB(A) | 2 yr (up to 7) | £10,000 to £16,000 |
| NIBE S2125 | Buyers who put quiet running and a long warranty first, and will use a NIBE Pro installer | 4.8 / 3.71 | 49 dB(A) | 2 yr (up to 7) | Price on quote |
| Panasonic Aquarea | Homeowners who want a mainstream Japanese brand with R290 models, including a T-CAP unit that holds full output in cold weather | 4.71 / 3.57 | 53 dB(A) | 3 yr (up to 7) | Price on quote |
| Aira | Homeowners who want one company to handle design, installation and upkeep, and are happy to pay a monthly plan for 15-year cover | 4.62 / 3.52 | 56 dB(A) | 5 yr (up to 15) | £14,229 to £19,500 |
| Mitsubishi Electric Ecodan UK brand | Homes keeping their existing radiators, from a UK-built range | 4.62 / 3.48 | 54 dB(A) | 3 yr (up to 7) | £9,000 to £14,000 |
| Daikin Altherma | Buyers wanting a split system with a small outdoor unit, or 70°C flow for radiators (3 H HT) | 4.47 / 3.54 | 54 dB(A) | 2 yr (up to 7) | £7,000 to £14,000 |
| Worcester Bosch UK brand | Homes where noise matters most, or Worcester boiler owners staying with the brand | 4.54 / 3.29 | 42 dB(A) | 2 yr (up to 7) | £9,000 to £14,000 |
| Octopus Cosy UK brand | Price-led switchers happy to buy and install through Octopus | 4.36 / 3.43 | 56 dB(A) | 8 yr | £8,000 to £12,000 |
| Samsung EHS | Buyers using an independent MCS installer who want a high-temperature monobloc | 4.46 / 3.22 | 56 dB(A) | Not published | £8,000 to £12,000 |
| Viessmann Vitocal | Smaller or new-build homes wanting a quiet R290 unit | 4.2 / 3.46 | 51 dB(A) | 2 yr (up to 7) | £10,000 to £16,000 |
Sorted by certified efficiency: the MCS SCOP of each brand's most efficient model we track, at 35°C and 55°C flow. Sound power is the maker's declared figure, the like-for-like noise measure. Warranty shows the standard term and, in brackets, the longest available with conditions. Prices are PumpSwap's indicative installed figures, not quotes, and are not used to rank brands.
How to choose
- Start with the installer, not the badge. A room-by-room heat loss survey and a low flow temperature design decide your running costs more than the brand does.
- Match the unit to your radiators. Keeping old radiators usually means a higher flow temperature; some ranges handle that better, but bigger radiators often pay back in efficiency.
- Compare warranties properly. The longest terms usually depend on an accredited installer and registering the product.
- Check the grant route. In England and Wales the installer must be MCS-certified to claim the £7,500 Boiler Upgrade Scheme grant (£9,000 for off-gas homes on oil or LPG).
- Ask about siting. Where the outdoor unit goes matters for noise and planning rules; your installer should check it meets the MCS standard.
The brands in brief
LG Therma V
SCOP 5.33 / 3.86 (35°C / 55°C) · sound power 49 dB(A) · warranty 3 yr (up to 7) · South Korea · no published installed price
LG's Therma V R290 Monobloc is a self-contained outdoor unit using R290 refrigerant, sold in the UK through dealers and installers, with LG installer training in Weybridge and Derby. It comes in 7, 9, 12, 14 and 16 kW sizes, runs down to -28°C and can supply water at up to 75°C. The 9 kW and 12 kW models are rated A+++ at both 35°C and 55°C and are listed by Quiet Mark.
- R290 refrigerant, rated A+++ at both 35°C and 55°C flow
- Quiet Mark listed (9 kW and 12 kW), with 49 to 50 dB(A) declared sound power
- Strong cold-weather output: 9.0 kW (9 kW model) and 11.8 kW (12 kW model) at -7°C
- Large and heavy: the 12 kW unit is 1,560 mm wide and weighs 181 kg
- LG UK's warranty pages do not say what qualifies for the extended term
- Standard warranty is 3 years, and LG requires servicing 'biannually'
Best for: Homeowners who want a quiet R290 monobloc with strong cold-weather output from a major electronics brand. LG vs Mitsubishi · LG vs Daikin · LG vs Vaillant
Ideal Logic Air
SCOP 5.09 / 3.63 (35°C / 55°C) · sound power 55 dB(A) · warranty Not published · UK · no published installed price
Ideal Heating is a Hull-based boiler maker, owned by France's Groupe Atlantic, that builds its Logic Air monobloc heat pumps in Hull. The Logic Air uses R32 refrigerant, comes in 4, 5, 8 and 10 kW sizes and is Quiet Mark certified. Ideal also sells the newer HP290 monobloc range, which uses R290.
- Built in Hull by a UK-headquartered heating manufacturer
- Quiet Mark certified
- Up to 7-year parts and labour warranty when registered within 30 days and serviced annually
- Uses R32 refrigerant rather than R290 (Ideal's R290 option is the separate HP290 range)
- 55 dB(A) declared sound power, higher than the Panasonic, NIBE and LG models here (49 to 54 dB(A))
- MCS directory SCOP for the 10 kW (4.57 at 35°C) is well below Ideal's published 5.19
Best for: Households who want a UK-built heat pump from a familiar boiler brand, installed through Ideal's installer network. Ideal vs Mitsubishi · Ideal vs Daikin · Ideal vs Vaillant
Grant Aerona3
SCOP 5.2 / 3.47 (35°C / 55°C) · sound power 64 dB(A) · warranty 1 yr (up to 7) · Ireland · indicative £8,000 to £13,000 installed
Grant, which also makes oil boilers, sells the Aerona3 R32 monobloc through its network of Grant-trained G1 installers. The 10 kW model has a certified SCOP of 5.2 at 35°C (MCS) and is rated to work down to -20°C. Off-gas homes in England and Wales replacing oil or LPG heating can get £9,000 off until 31 March 2027.
- Certified SCOP of 5.2 at 35°C (MCS)
- Compact and light (70 kg)
- 7-year warranty through a G1 installer
- High sound power (64 dB(A)), so siting matters
- Maximum flow temperature 60°C, lower than R290 units
- Standard warranty only 12 months unless registered
Best for: Off-gas homes replacing oil or LPG heating, where the £9,000 grant can apply in England and Wales. Grant Aerona vs Mitsubishi · Grant Aerona vs Daikin · Grant Aerona vs Vaillant
Vaillant aroTHERM plus
SCOP 4.88 / 3.63 (35°C / 55°C) · sound power 55 dB(A) · warranty 2 yr (up to 7) · Germany · indicative £10,000 to £16,000 installed
Vaillant's aroTHERM plus uses natural R290 refrigerant and reaches 75°C flow. It is the most common model in heatpumpmonitor.org's public data (305 of 813 systems on 7 October 2026), where its measured median efficiency over a full year, 4.06 across 147 systems, is among the highest of any brand. A new aroTHERM plus launched in the UK in June 2026, and the /6 models shown here are being run out.
- Natural R290 refrigerant, up to 75°C flow
- Quiet Mark certified (except the 10 kW)
- Among the best measured real-world efficiency on heatpumpmonitor.org (median 4.06)
- Standard warranty is 2 years; 7 needs a Vaillant cylinder and a partner installer
- The /6 range is being replaced by a new model launched in June 2026
- The 12kW outdoor unit is tall (1,565 mm) and heavy (194 kg)
Best for: Efficiency-first buyers who want a proven, widely monitored unit. Vaillant vs Mitsubishi · Vaillant vs Daikin · Vaillant vs Octopus Cosy
NIBE S2125
SCOP 4.8 / 3.71 (35°C / 55°C) · sound power 49 dB(A) · warranty 2 yr (up to 7) · Sweden · no published installed price
NIBE is a Swedish heat pump maker whose UK company, NIBE Energy Systems, is based in Chesterfield. The S2125 is its R290 monobloc air source heat pump, sold in the UK in 8, 12, 16 and 20 sizes, with the 8 and 12 Quiet Mark certified. NIBE says it has over 40,000 heat pumps installed in the UK and also sells installations directly through its NIBE Home service.
- R290 refrigerant
- Quiet Mark certified (S2125-8 and S2125-12) with 49 dB(A) declared sound power
- Up to 75°C flow, and up to 65°C at -25°C outdoor
- Standard warranty is 2 years unless a NIBE Pro installer registers the extended cover
- Heavy and deep: 163 kg and 831 mm deep for both the 8 and 12
- Size labels overstate output: the S2125-12 is rated 6.8 kW at 35°C, 8.34 kW maximum at -7°C
Best for: Buyers who put quiet running and a long warranty first, and will use a NIBE Pro installer. NIBE vs Mitsubishi · NIBE vs Daikin · NIBE vs Vaillant
Panasonic Aquarea
SCOP 4.71 / 3.57 (35°C / 55°C) · sound power 53 dB(A) · warranty 3 yr (up to 7) · Japan · no published installed price
Panasonic sells its Aquarea air-to-water heat pumps in the UK through trained installers. The current L Series and T-CAP M Series use R290 refrigerant and supply water at up to 75°C, and ScottishPower's installer Plug Me In fits Aquarea for ScottishPower customers. British Gas signed a service and maintenance deal with Panasonic in March 2025.
- R290 refrigerant in both the L Series and T-CAP M Series
- Water flow temperatures up to 75°C for radiator systems
- T-CAP M Series 12 kW keeps its full 12 kW output at -7°C outdoor
- The 7-year warranty only applies when a PRO Partner installer registers it
- T-CAP M Series outdoor units are large and heavy: 1,520 mm tall and 161 kg
- L Series 9 kW output falls to 7.0 kW at 2°C and -7°C outdoor (35°C flow)
Best for: Homeowners who want a mainstream Japanese brand with R290 models, including a T-CAP unit that holds full output in cold weather. Panasonic vs Mitsubishi · Panasonic vs Daikin · Panasonic vs Vaillant
Aira
SCOP 4.62 / 3.52 (35°C / 55°C) · sound power 56 dB(A) · warranty 5 yr (up to 15) · Sweden · indicative £14,229 to £19,500 installed
Aira is a Swedish company that designs its own R290 heat pump, builds it in Wroclaw, Poland, and sells and installs it directly to UK homes. It offers 6, 8 and 12 kW outdoor units, publishes real-world performance data from UK installs, and bundles a 15-year guarantee into a paid all-inclusive plan. As with Octopus Cosy, you cannot buy an Aira unit through an independent installer. We list the 8 kW: Aira does not publish the weight or sound power of the single-phase 12 kW.
- Designed, sold, installed and maintained by Aira itself
- R290 refrigerant, rated A+++ at 35°C
- 15 years of parts, labour and maintenance cover on the All Inclusive Plan (first year free)
- Only available through Aira, so there are no competing quotes on the same hardware
- Without the paid plan, the product warranty is 5 years, parts only, with no labour
- Aira's headline SCOP of 4.7 is above its MCS-listed figures (4.40 to 4.62)
Best for: Homeowners who want one company to handle design, installation and upkeep, and are happy to pay a monthly plan for 15-year cover. Aira vs Mitsubishi · Aira vs Daikin · Aira vs Vaillant
Mitsubishi Electric Ecodan
SCOP 4.62 / 3.48 (35°C / 55°C) · sound power 54 dB(A) · warranty 3 yr (up to 7) · Japan / UK · indicative £9,000 to £14,000 installed
Mitsubishi Electric builds its Ecodan heat pumps in Livingston, Scotland. The current R290 range runs from 5 to 12 kW, reaches flow temperatures up to 75°C for homes keeping their radiators, and the 8.5, 10 and 12 kW sizes all come in single phase.
- Made in Livingston, Scotland
- R290 range reaches 75°C flow, so existing radiators can often stay
- Quiet Mark certified (R290 8.5, 10 and 12 kW)
- Standard warranty is 3 years; 7 needs a top-tier Mitsubishi installer
- Single-phase 10 and 12 kW units need a dedicated 32 A or 40 A supply
Best for: Homes keeping their existing radiators, from a UK-built range. Mitsubishi vs Daikin · Mitsubishi vs Vaillant · Mitsubishi vs Octopus Cosy
Daikin Altherma
SCOP 4.47 / 3.54 (35°C / 55°C) · sound power 54 dB(A) · warranty 2 yr (up to 7) · Japan · indicative £7,000 to £14,000 installed
Daikin's Altherma 3 range covers split and monobloc air-to-water heat pumps. The Altherma 3 R split pairs a compact outdoor unit with an indoor hydrobox; the Altherma 3 H HT reaches 70°C flow for homes keeping their radiators. Daikin rates the 3 R to keep working down to -25°C and the 3 H HT to -28°C.
- Split design with a compact outdoor unit (58.5 kg for the 3 R 8kW)
- Altherma 3 H HT reaches 70°C flow for radiator systems
- Rated to work down to -25°C (3 R) and -28°C (3 H HT)
- Standard warranty is 2 years; 5 needs Stand By Me activation and annual maintenance
- The 3 R 8kW has a high sound power (62 dB(A)), so siting matters
Best for: Buyers wanting a split system with a small outdoor unit, or 70°C flow for radiators (3 H HT). Daikin vs Mitsubishi · Daikin vs Vaillant · Daikin vs Octopus Cosy
Worcester Bosch
SCOP 4.54 / 3.29 (35°C / 55°C) · sound power 42 dB(A) · warranty 2 yr (up to 7) · UK · indicative £9,000 to £14,000 installed
Worcester Bosch, the Bosch-owned heating maker based in Worcester, has sold heat pumps in the UK since 2006 through its accredited installers. Its Compress 5800i AW uses natural R290 refrigerant, reaches 75°C flow and has a declared sound power of 42 dB(A) for the 7 kW model.
- Declared sound power of 42 dB(A) for the 7 kW
- Natural R290 refrigerant, up to 75°C flow
- Selling heat pumps in the UK since 2006
- Standard warranty is 2 years; 7 needs registration and annual servicing
- Heavy for a 7 kW unit (143 kg)
Best for: Homes where noise matters most, or Worcester boiler owners staying with the brand. Worcester Bosch vs Mitsubishi · Worcester Bosch vs Daikin · Worcester Bosch vs Vaillant
Octopus Cosy
SCOP 4.36 / 3.43 (35°C / 55°C) · sound power 56 dB(A) · warranty 8 yr · UK · indicative £8,000 to £12,000 installed
Octopus Energy's own heat pump, designed and built in the UK at its factory in Craigavon, Northern Ireland, and installed by Octopus or its Cosy Accredited Installers. Octopus says its median quote was £4,064 after the £7,500 grant (quotes from 1 June to 30 September 2026). It pairs with the Cosy Octopus tariff, which works with any heat pump.
- Octopus median quote £4,064 after the grant (June to September 2026)
- Designed and built in the UK
- 8-year hardware warranty as standard
- Only available through Octopus or its accredited installers
- Newer hardware: Cosy 6 launched in late 2023, Cosy 9 in 2025
Best for: Price-led switchers happy to buy and install through Octopus. Octopus Cosy vs Mitsubishi · Octopus Cosy vs Daikin · Octopus Cosy vs Vaillant
Samsung EHS
SCOP 4.46 / 3.22 (35°C / 55°C) · sound power 56 dB(A) · warranty Not published · South Korea · indicative £8,000 to £12,000 installed
Samsung's EHS Mono HT Quiet is a monobloc heat pump that reaches 70°C flow. Samsung launched it in 2022 as the first model in its premium high-temperature line-up, with a quiet mode rated at 35 dB(A) at 3 metres.
- Reaches 70°C flow for radiator systems
- Quiet mode rated at 35 dB(A) at 3 metres
- Monobloc design, with refrigerant kept in the outdoor unit
- UK warranty terms not published, so check what your installer offers
Best for: Buyers using an independent MCS installer who want a high-temperature monobloc. Samsung vs Mitsubishi · Samsung vs Daikin · Samsung vs Vaillant
Viessmann Vitocal
SCOP 4.2 / 3.46 (35°C / 55°C) · sound power 51 dB(A) · warranty 2 yr (up to 7) · Germany · indicative £10,000 to £16,000 installed
Viessmann, the German heating brand that is now part of Carrier, makes the Vitocal 150-A, an R290 monobloc that reaches 70°C flow. Viessmann UK positions its 4, 6 and 8 kW outdoor units for new builds and the 10 to 16 kW units for retrofits.
- Natural R290 refrigerant, up to 70°C flow
- Declared sound power of 51 dB(A)
- Standard warranty is 2 years; 7 costs £360
- MCS-certified SCOP (4.2 at 35°C) is below the maker's own 4.4
- Heavy for its rated output (162 kg)
Best for: Smaller or new-build homes wanting a quiet R290 unit. Viessmann vs Mitsubishi · Viessmann vs Daikin · Viessmann vs Vaillant
Frequently asked questions
What is the best air source heat pump in the UK?
There is no single best one: the right choice depends on your home, your radiators and the installer. On certified figures, the Therma V R290 Monobloc 12kW has the highest efficiency of the models we track (MCS SCOP 5.33 at 35°C and 3.86 at 55°C), the Compress 5800i AW 7kW has the lowest declared sound power (42 dB(A)), and Octopus Cosy offers the longest standard warranty (8 years). A good installer's design matters as much as the badge.
Which air source heat pump is the most efficient?
Of the models we track, the Therma V R290 Monobloc 12kW has the highest certified efficiency across the two standard tests: an MCS SCOP of 5.33 at 35°C flow and 3.86 at 55°C. Efficiency falls as the water gets hotter, so a system designed to run cool, with bigger radiators or underfloor heating, gets more from any good unit than a poorly designed system gets from the most efficient one.
Which air source heat pump is the quietest?
On the makers' declared sound power, the like-for-like noise figure, the Compress 5800i AW 7kW is the quietest unit we track at 42 dB(A). What a neighbour hears is much lower than sound power and falls with distance, and permitted development rules require the installation to meet the MCS noise standard at their window, so siting matters as much as the unit.
Does the brand affect the £7,500 grant?
No. The Boiler Upgrade Scheme in England and Wales and the Home Energy Scotland grant are not tied to a brand. What matters is that your installer is MCS-certified and the product is MCS-certified. Northern Ireland has no equivalent grant.
Are UK-made heat pumps better?
Not automatically. Mitsubishi Electric Ecodan, Octopus Cosy, Worcester Bosch and Ideal Logic Air are UK-built or UK-headquartered, which can mean familiar service networks, but efficiency, warranty and the installer's design matter more than where the unit is made.
Heat pump costs by region
Heat pump guides
- Air source heat pump installation cost in the UK
- The £7,500 Boiler Upgrade Scheme, explained
- Air source heat pumps: costs, grants and brands
- Heat pump grants in London
- Heat pump grants in South East England
- Heat pump grants in South West England
- Heat pump grants in East of England
- Heat pump grants in East Midlands
- Heat pump grants in West Midlands
- Heat pump grants in Yorkshire and the Humber
- Heat pump grants in North West England
- Heat pump grants in North East England
- Heat pump grants in Scotland
- Heat pump grants in Wales
- Heat pump grants in Northern Ireland
Where are you?
See indicative costs and local installers for your area