Best heat pump brands UK 2026: 8 models compared

Quick answer: Grant’s Aerona 290 is our pick of the heat pumps UK homeowners get quoted in 2026: five sizes from 4 to 15.5kW, SCOP up to 3.74 at 55°C and a 7-year guarantee through a G1 installer. Mitsubishi’s Ecodan R290 and NIBE’s S2125 run it close. Any of the eight below can attract the £7,500 Boiler Upgrade Scheme grant when an MCS-certified installer fits an MCS-listed model.

We haven’t tested any of these units. This ranking compares manufacturers’ published datasheets, MCS-listed figures, warranty terms and prices, all checked on 25 September 2026.

How we ranked them

Brochures lead with the SCOP at 35°C flow, the figure for a house with underfloor heating throughout. Most British homes aren’t that. So efficiency at 55°C carries the most weight here, because most boiler swaps keep some radiators. We weighed it against size range, because an oversized unit cycles on and off all winter, and against the warranty you can really get and what it costs. That’s why NIBE, with the best 55°C figures, sits third (its smallest unit is 8kW) and Viessmann sits seventh (its 7-year cover costs £360). Price broke ties.

The 2026 ranking at a glance

The eight, one by one

1. Grant Aerona 290: best overall

Grant sells one of the widest spreads of sizes here, which matters more than any single efficiency number: an installer can fit a 4kW or 6.5kW unit to a small house instead of rounding up to 8kW. Four of the five sizes post 3.62 or better at 55°C on Grant’s own figures, and the 4kW is rated at 48 dB(A) sound power (Grant installation manual, April 2026). Octopus Energy now fits the 15.5kW model for larger, harder-to-heat homes (Octopus).

The weak spot is the base guarantee: 12 months, rising to two years only if you register within 30 days and service it annually. The 7 years needs a G1 installer. The 15.5kW also drops to 3.33 at 55°C. Our NIBE vs Grant comparison goes further.

2. Mitsubishi Ecodan R290: the quiet, British-built all-rounder

Five sizes from 5 to 12kW, MCS-listed SCOPs of 3.38 to 3.51 at 55°C, and 40 dB(A) sound pressure at one metre on every model. Mitsubishi makes it at its factory in Livingston, Scotland (Mitsubishi Electric), and sells coastal-protection versions for sites near the sea. The warranty ladder is simple: up to 3 years through a standard installer, 5 through an Accredited Ecodan Installer, 7 through a Business Solutions Partner. It stops at 12kW, so very large houses need something else. See our Ecodan review.

3. NIBE S2125: best on paper, if your house is big enough

The S2125 has the best 55°C figures we found: 3.70 on the 8kW and 3.80 on the 12kW. It’s also the only one that publishes cold-climate SCOPs, and NIBE says it still delivers 65°C flow at -25°C outside. The problem is size. The smallest model is 8kW, which is too big for a lot of semis. The standard warranty is also thin at 24 months, and the 7 years needs a Pro Partner, registration within 28 days, yearly servicing and, within a kilometre of the coast, Blygold anti-corrosion coating. Read our NIBE review.

4. Samsung EHS Mono R290 Gen 7: best budget pick

The 8kW was listed at £2,283.44 excluding VAT, supply only, at The Heat Pump Warehouse on 25 September 2026 (listing). Its MCS-listed SCOPs sit level with Mitsubishi’s at 55°C, and the datasheet gives a figure in 5°C steps from 35 to 65°C, which few rivals do. Noise is its weak point: sound power runs from 55 dB(A) on the 5kW to 65 dB(A) on the 16kW, the highest single figure in this table, though the 8kW’s 59 dB(A) is below Daikin’s 8kW at 62. Samsung’s UK product page doesn’t state a warranty length; its own registration form offers 7 years through an approved installer. See our Samsung vs LG comparison.

5. Vaillant aroTHERM plus: best for small, well-insulated homes

The 3.5kW model is the smallest unit in this table, and Vaillant’s installation manual rates the 3.5 and 5kW at 51 dB(A) sound power (Vaillant manual). The 10kW posts 5.03 at 35°C. But the small sizes are the weakest here at 55°C, 3.10 and 3.06. So it shines in a tight, well-insulated home running 35 to 45°C, and it’s a poorer fit on undersized radiators. The full 7 years also ties you to a Vaillant cylinder and a Platinum or Renewable Partner installer. Vaillant has launched a restyled aroTHERM plus it calls its most efficient yet (Vaillant); our figures come from its March 2024 installer guide, so ask which version you’re quoted. More in our aroTHERM plus review.

6. Octopus Cosy: longest warranty, one company start to finish

Octopus designs, builds and installs the Cosy itself, and gives it an 8-year warranty, the longest here, without making an annual service a condition. It reaches 70°C and publishes a 65°C SCOP of 2.8 to 3.3, which is candid. You can’t shop the unit around to other installers, though, and Octopus’s “designed at 50°C” SCOPs aren’t measured the same way as the others. It’s the easy route if you’re happy with Octopus doing everything; our Octopus vs OVO comparison covers the package.

7. Viessmann Vitocal 150-A and 151-A

A well-specified propane unit: 70°C flow down to -10°C outside, 3.51 to 3.61 at 55°C on the 4 to 8kW models, and 51 dB(A) sound power on the smaller sizes in night mode (Viessmann brochure). It ranks seventh on the warranty. The standard term is 2 years, and Viessmann charges £360 to take it to 7, cover several rivals include free with the right installer.

8. Daikin Altherma 3 M: fine on underfloor, wrong for old radiators

The Altherma 3 M runs on R32 and stops at 65°C flow. At 35°C it’s competitive; at 55°C it posts 3.28 to 3.35, towards the bottom of this table. Daikin gives 2 years, 5 free if you register on Stand By Me within two years of commissioning, and 7 only as a paid extension through a Sustainable Home Expert. Daikin’s propane replacement, the Altherma 4, added 4, 6 and 7kW classes in January 2026 with 70°C flow at -15°C outside (Daikin), but that announcement gives no SCOP. If you’re quoted one, ask for its MCS listing. More in our Daikin vs Mitsubishi comparison.

Which heat pump has the best warranty?

On length, Octopus: 8 years on the Cosy, and on the Grant Aerona 290 15.5kW it fits, though that one needs a yearly service (Octopus). Everyone else tops out at 7, and the route to 7 matters more than the number:

• Free with the right installer: Mitsubishi (Business Solutions Partner), Grant (G1 installer), NIBE (Pro Partner, registered within 28 days) and Samsung (approved installer, registered within 30 days of commissioning).
• Free, but only with extra kit: Vaillant, which needs a Vaillant hot water cylinder and a Platinum or Renewable Partner installer.
• Paid: Daikin (through a Sustainable Home Expert) and Viessmann (£360).

Most of them also require an annual service to keep the cover. Our advice is blunt: ignore the brochure maximum, ask the installer which tier they hold, and get the warranty length written on the quote. Our heat pump warranty guide lists what to check.

The best R290 heat pump manufacturers in the UK

Seven of our eight now run on R290, which is propane. Mitsubishi and Viessmann print its global warming potential as 0.02, the IPCC’s latest figure (Grant and Samsung still quote the older figure of 3), against 675 for R32. Propane also reaches 70 to 75°C flow, which is why the R290 generation can work with ordinary radiators. It’s flammable, so installers must keep a clear zone around the outdoor unit. That’s manageable, but it can rule out a narrow side passage.

If you’re replacing a boiler in 2026, buy R290. The only R32 unit here, Daikin’s Altherma 3 M, is still sold, but its 65°C ceiling leaves no headroom on a cold day. Our R32 vs R290 guide explains the trade-offs.

Best heat pump brands for cold British winters

British winters aren’t the problem people think. The design temperatures installers use under MCS’s MIS 3005 standard range from -3.9°C in Glasgow and -3.4°C in Birmingham to -0.2°C in Plymouth (quoted in Vaillant’s installer guide). Mitsubishi, Grant, NIBE and Daikin publish operating ranges down to -25°C, and Daikin’s Altherma 4 claims -28°C.

What matters is output at around -3 to -5°C at your flow temperature, and how the unit copes with damp weather hovering just above freezing, when the outdoor coil ices and has to defrost. A few makers publish the useful numbers. NIBE gives cold-climate SCOPs of 3.20 to 3.40 at 55°C. Grant’s 9kW still delivers 9.21kW at -5°C outside and 55°C flow. Vaillant’s 7kW gives 7kW at -5°C and 55°C. For exposed, cold sites we’d pick NIBE if the size fits and Grant if it doesn’t. Near the sea, check the coastal conditions: NIBE requires coating within a kilometre of the shore, and Mitsubishi sells coastal versions. Our defrost cycle guide explains the icing problem.

Who makes them, and where they’re made

• Mitsubishi Electric builds the Ecodan R290 in Livingston, Scotland, and describes the plant as the largest heat pump manufacturer in the UK.
• Octopus makes the Cosy in Craigavon, Northern Ireland (Octopus, September 2023).
• Grant is an Irish firm with its headquarters in Birr, County Offaly (Grant), where it has had a factory since 1981 (Grant heritage). Its UK declaration of conformity names Grant Engineering (UK) Ltd in Swindon as manufacturer, but Grant doesn’t say where the Aerona 290 outdoor unit is assembled.
• NIBE runs its head office and its own factories in Markaryd, Sweden (NIBE).
• Viessmann’s product data names Viessmann Climate Solutions in Allendorf, Germany; US group Carrier completed its purchase of the business on 2 January 2024 (Carrier).
• Vaillant is a German group with its UK base in Belper, Derbyshire. Daikin’s European headquarters is in Ostend, Belgium, and Samsung’s head office is in Suwon, South Korea. None of the three states on the pages we checked where these specific units are built.

Who’s the largest? There’s no public league table of UK heat pump sales by brand. MCS certifies every grant-funded installation but, as far as we could find, doesn’t publish brand shares. All eight companies were trading when we checked, including Grant Engineering (UK) Ltd, listed as active at Companies House.

What is the best heat pump for the money?

The median air source installation under the Boiler Upgrade Scheme cost £12,908 in April to June 2026, including the grant value (DESNZ statistics, August 2026 release). Take off £7,500 and the typical homeowner paid about £5,408. Octopus says its median quote after the grant was £4,459 between September 2025 and February 2026. Our own heat pump cost index puts a typical three-bed air source job at £10,684 including VAT.

For best value, pick Samsung or Grant if you want to choose your own installer, and the Octopus Cosy if you’d rather have one fixed package. Then spend the money you save on the unit on bigger radiators. Lowering your design flow temperature from 55°C to 45°C lifts SCOP by 0.5 to 0.7 on the Samsung and Vaillant units, which publish both figures. That’s more than the gap between most of the brands here.

Best heat pump for older homes

Choose an R290 unit that reaches 70 to 75°C, then design the system to run at 50 to 55°C by upsizing the handful of radiators that need it. Grant, Mitsubishi and NIBE all fit that brief. Avoid 65°C-limited R32 units if you’re keeping original radiators. We cover models, break-even SCOPs and grants in our guide to the best heat pumps for older homes.

The installer matters more than the badge

The government-funded Electrification of Heat trial monitored hundreds of heat pumps in real homes. It found no significant difference in performance by house type or age, but a wide spread overall, which it put down to inconsistent design and installation. The median air source result was a seasonal performance factor of 2.78 (Energy Systems Catapult, December 2024).

Put that in money. A house needing 12,000kWh of heat a year pays about £929 at SCOP 3.4 and £854 at SCOP 3.7 under the October to December 2026 price cap of 26.32p/kWh. That’s £75 between a good brand and a very good one. At 2.78 the same house pays £1,136. Design and commissioning move your bill far more than the logo on the fan. Read what a good heat pump quote looks like before you sign, then request a free quote: up to three approved installers who cover your area may contact you. No charge, no obligation.

This ranking is based on manufacturer datasheets, warranty terms, MCS-listed figures and government statistics, all checked on 25 September 2026.

FAQs

Which heat pump is best for the UK?

For most UK homes, the Grant Aerona 290. It has one of the widest size ranges of the R290 units we compared, SCOPs of 3.62 to 3.74 at 55°C on four of its five sizes, and up to 7 years’ guarantee through a G1 installer. Mitsubishi’s Ecodan R290 is a close second.

Which heat pump brand has the best warranty?

Octopus gives 8 years on the Cosy and on the Grant 15.5kW it fits. Mitsubishi, Grant, NIBE and Samsung offer up to 7 years free through their top installer tiers, Vaillant offers 7 with its own cylinder, and Daikin and Viessmann charge for the last years.

What is the most efficient heat pump?

At 55°C flow, the NIBE S2125 12kW at a published 3.80, with Grant’s 12kW at 3.74. At 35°C, Grant’s 6.5kW leads at 5.08 and Vaillant’s 10kW posts 5.03. Test bases differ, so treat small gaps as a tie.

Where are Grant heat pumps made?

Grant is an Irish company based in Birr, County Offaly, with its UK arm in Swindon. Grant Engineering (UK) Ltd is named as manufacturer on the Aerona 290’s UK declaration, but Grant doesn’t publish where the outdoor unit is assembled.

Do all these heat pumps qualify for the £7,500 grant?

Yes, in England and Wales, provided the exact model is MCS-listed and an MCS-certified installer fits it. Homes heated by oil or LPG with no mains gas can get £9,000 until 31 March 2027. Our Boiler Upgrade Scheme guide has the details.