Daikin Heat Pump Review UK: Altherma Range, Pricing & Verdict

Daikin is the world's largest heating, ventilation and air-conditioning manufacturer, and its Altherma 3 air source heat pump range is a familiar sight on UK installer vans alongside Mitsubishi Ecodan and Vaillant aroTHERM. This review covers what's actually in the current UK range, what it costs installed before and after the Boiler Upgrade Scheme (BUS) grant, warranty terms, noise levels, MCS/BUS eligibility, and an honest comparison with the two rival brands already reviewed on this site.

Company background

Daikin Industries was founded in 1924 in Osaka, Japan, and has grown into a group of around 96,000 employees selling in more than 170 countries, widely cited in trade press as the world's largest HVAC manufacturer by revenue. UK and European sales run through Daikin Europe N.V., headquartered in Ostend, Belgium, which operates 14 manufacturing sites across Europe, the Middle East and North Africa. It's worth being precise here: Daikin does have UK factories, but they build commercial equipment — chillers at Cramlington and refrigeration/air-curtain products at Ipswich — not the residential Altherma units sold for home heating, which are built in Belgium, the Czech Republic and Germany.

The current Altherma range

Daikin's domestic heat pump line-up sits under the Altherma 3 name and splits into a few distinct product families:

Altherma 3 M is the standard monobloc — the whole refrigerant circuit stays outside in a single compact unit (770×1250×362mm for the smaller sizes), available from 4kW up to 16kW, running on R32 refrigerant with flow temperatures up to 55°C at -15°C outside air temperature and built-in Wi-Fi control.

Altherma 3 H HT is a high-temperature monobloc aimed specifically at retrofits onto an existing radiator system without swapping the radiators for larger ones — it can push flow temperatures higher than the standard M range, competing directly with Mitsubishi's and Vaillant's own high-temperature retrofit models.

Altherma 3 R-Split is a split system (11–16kW classes) with the refrigerant circuit running between an outdoor unit and an indoor hydrobox, rather than everything staying outside — this suits some retrofit layouts but means an F-Gas-qualified engineer handling refrigerant pipework inside the house, unlike the monobloc models.

A note on refrigerant: Daikin has begun launching R290 (propane) heat pumps, which have a far lower global warming potential than R32 — but as of 2026 the confirmed R290 launches are commercial-scale units (17kW and up), not a domestic Altherma-branded product. If you see a UK "R290 Daikin" heat pump marketed for a home, check carefully whether it's a genuine Daikin Altherma model or a third-party product built around Daikin components.

UK installed pricing

A full Altherma installation — unit, hot-water cylinder and labour — typically runs £9,500 to £14,500 for a 3–4 bed home before any grant, based on UK installer and comparison-site pricing, with the unit itself accounting for roughly £3,000–£9,000 of that depending on size and model tier.

The Boiler Upgrade Scheme grant applies the same way to Daikin as any other MCS-certified air source heat pump: £7,500 off the installed cost, taken as a discount on the installer's invoice rather than a homeowner claim. Off-gas-grid households (no mains gas connection) can add a further £1,500 uplift introduced in 2026, bringing the maximum grant to £9,000. That can bring realistic out-of-pocket cost down to roughly £0–£7,000 depending on system size and site.

Warranty

Daikin's warranty structure has more tiers than a single flat number: the standard cover is 2 years, automatic with no registration required. Installing and registering the unit with a Daikin Sustainable Home Installer on Daikin's "Stand By Me" platform within two years of commissioning extends that to 5 years free of charge. Using a top-tier Sustainable Home Expert installer unlocks a 7-year paid extension, and installer trade sources cite cover as long as 12 years available for D1+-registered installers who keep the unit on an annual service contract — worth asking about, but conditional on ongoing maintenance rather than a simple one-off registration. Get the exact warranty terms and installer tier confirmed in writing before signing anything.

Noise

Daikin publishes model-specific noise figures rather than one number for the whole range. The Altherma 3 H HT, for example, is rated at 54 dB(A) sound power, with sound pressure of 38 dB(A) at 3 metres in standard operation, dropping to 35 dB(A) at 3 metres in low-sound mode, and a further ~3dB(A) quieter with the optional Low Sound Cover. That model holds third-party Quiet Mark certification. These figures are specific to the H HT unit — always check the datasheet for the exact model and size being quoted, since smaller and larger units in the range will differ.

MCS certification and BUS eligibility

Altherma products are MCS-certified, and BUS applications go through Daikin's network of MCS-registered installers in the same way as any other manufacturer — there's no Daikin-specific restriction on grant eligibility. As with any brand, always confirm the specific model is currently MCS-listed and that your chosen installer is MCS-certified for heat pumps specifically (not just for solar or another technology), since this is what unlocks both the BUS grant and Smart Export Guarantee-adjacent paperwork if you're also running solar PV on the property. See our guide to MCS certification for what to check.

How Daikin compares

Daikin, Mitsubishi Ecodan and Vaillant aroTHERM are the three brands UK installers reach for most often, and on paper they're closer than the marketing suggests. Daikin's monobloc-first approach (keeping the refrigerant circuit entirely outdoors) mirrors Vaillant's aroTHERM plus design and avoids the indoor F-Gas pipework that Mitsubishi's split Ecodan models and Daikin's own R-Split range both require. All three now offer a dedicated high-temperature retrofit model aimed at homes keeping their existing radiators, so that's a genuine three-way race rather than a Daikin exclusive.

Where Daikin stands out is warranty structure: its tiered 2/5/7/12-year ladder, gated behind installer accreditation level and (at the top end) an ongoing service contract, is more layered and conditional than Vaillant's more straightforward 2-to-7-year extension via a single Advance-installer tier. That's not necessarily worse, but it means more paperwork to track if you want the longest cover. On noise, the Altherma 3 H HT's Quiet Mark certification puts it in the same bracket as Vaillant's aroTHERM plus, which also carries Quiet Mark on four of its five output variants — neither brand has a clear edge here on the figures published so far.

All three brands sell through deep, MCS-accredited UK installer networks, so availability of parts and experienced engineers is unlikely to be the deciding factor between them for most homeowners — get quotes from installers who work with more than one brand and compare the specific model, warranty tier and price on the table, not the badge on the unit.

Our verdict

Daikin Altherma is a safe, well-supported choice backed by the scale of the world's largest HVAC manufacturer, with a genuinely useful high-temperature retrofit option in the H HT model for homes that don't want to replace radiators. It isn't obviously cheaper or quieter than Mitsubishi or Vaillant on the figures available, so the practical decision usually comes down to which brand your local MCS-certified installer knows best, what warranty tier they can actually offer, and how the final quoted price compares after the £7,500 (or £9,000 off-gas-grid) BUS grant. For the fundamentals of what SCOP and running costs actually mean for your bill, see our guide to heat pump running costs.