Home Heat Pump Guide

Daikin Heat Pump Review UK

Daikin is one of the most recognised names in the heat pump market worldwide. The Japanese manufacturer has been producing heating and cooling equipment for nearly a century and operates one of the largest heat pump manufacturing facilities in Europe, based in Belgium. In the UK, Daikin's Altherma range of air-to-water heat pumps is among the most commonly installed, with a strong installer network and a reputation for reliable performance.

This review covers the current Daikin Altherma range available in the UK, including real-world performance data, noise levels, pricing, warranty terms, and an honest assessment of the pros and cons.

The Daikin Altherma Range

Daikin's domestic air-to-water heat pump line-up in the UK centres on the Altherma 3 range. There are several variants to suit different property types and requirements.

Daikin Altherma 3 R (Low Temperature)

The Altherma 3 R is Daikin's flagship low-temperature monobloc heat pump. It delivers maximum flow temperatures of 55°C, which is suitable for well-insulated homes with adequately sized radiators or underfloor heating.

  • Capacity range: 4kW to 16kW
  • Refrigerant: R32
  • SCOP (at 35°C): Up to 4.64 (varies by model size)
  • SCOP (at 55°C): Up to 3.19
  • Noise at 1m: 37 to 46dB (varies by model and output)
  • Max flow temperature: 55°C
  • Dimensions (outdoor unit): Varies by model, typically 735 x 884 x 390mm (WxHxD) for smaller models

This is the model most commonly installed in UK homes. The monobloc design means all refrigerant is contained within the outdoor unit — only water pipes connect the outdoor unit to the indoor system. This simplifies installation (no F-gas work needed inside the property) and reduces installation cost.

Daikin Altherma 3 H HT (High Temperature)

The high-temperature variant delivers flow temperatures up to 70°C, making it suitable for older properties with smaller radiators or solid-wall homes where low-temperature operation is not practical.

  • Capacity range: 9kW to 16kW
  • Refrigerant: R32
  • SCOP (at 55°C): Up to 3.30
  • Max flow temperature: 70°C
  • Noise at 1m: 40 to 48dB

The high-temperature model is less efficient at peak temperatures (COP drops as flow temperature rises), but it provides a practical solution for properties where radiator replacement is not feasible or where the fabric first approach cannot fully address heat loss.

Daikin Altherma 3 Geo (Ground Source)

Daikin also offers a ground source heat pump under the Altherma brand. This is less commonly installed than the air source range but is worth considering for properties with sufficient garden space, particularly in rural areas.

Real-World COP Performance

Manufacturer-stated SCOP figures are measured under controlled laboratory conditions (EN 14825 standard). Real-world performance in UK homes is typically slightly lower, depending on installation quality, system design, and how the homeowner uses the system.

Data from the UK's Electrification of Heat Demonstration Project and independent monitoring by organisations such as the Heat Pump Association suggests that well-installed Daikin Altherma 3 systems typically achieve seasonal COPs of:

  • 3.2 to 3.8 when running at flow temperatures of 35 to 40°C (well-insulated homes, UFH or large radiators)
  • 2.6 to 3.2 when running at flow temperatures of 45 to 55°C (older homes, standard radiators)
  • 2.0 to 2.7 when running the high-temperature model at 55 to 70°C

These figures are consistent with other leading brands. The key takeaway is that flow temperature has a far bigger impact on real-world COP than the brand of heat pump. A Daikin running at 35°C will significantly outperform any brand running at 55°C.

Noise Levels

Daikin's Altherma 3 range is among the quieter heat pumps on the market. The smallest models (4 to 6kW) achieve noise levels as low as 37dB at one metre — quieter than a typical library. Even the larger models (12 to 16kW) stay under 46dB at full output.

In practice, most heat pumps spend the majority of their operating time at partial load (not full output), which further reduces noise. Daikin's inverter-driven compressor modulates smoothly, avoiding the start-stop cycling that can cause noise complaints with on/off systems.

For properties close to neighbouring boundaries, the quiet operation of the Altherma 3 is a significant advantage. It comfortably meets the MCS noise standard (42dB at the nearest neighbour's window) in most typical UK installations.

Installation and Indoor Components

The Daikin system pairs the outdoor unit with indoor components that include:

  • Daikin Altherma integrated cylinder: A combined hot water cylinder and hydraulic module in a single unit, available in 180-litre and 230-litre sizes. This simplifies installation and reduces the indoor footprint.
  • Separate cylinder option: For larger hot water demands, a separate buffer tank and unvented cylinder can be used.
  • Daikin Madoka controller or EKRUCBL thermostat: Wall-mounted controllers with intuitive interfaces for setting schedules and temperatures.
  • Daikin ONECTA app: Cloud-based monitoring and control via smartphone. Allows remote temperature adjustment, scheduling, and basic energy monitoring.

Daikin's monobloc design means installation is relatively straightforward for experienced MCS installers. No F-gas certification is needed for the refrigerant circuit (it is factory-sealed in the outdoor unit). The main installation work involves positioning the outdoor unit, running insulated water pipes and electrical connections to the indoor unit, and connecting to the existing heating system.

Warranty and After-Sales Support

Daikin offers a 5-year manufacturer warranty as standard on all Altherma heat pumps. This can be extended to up to 10 years through Daikin's D1 partner programme — an installer accreditation scheme that recognises experienced and trained installers.

The warranty covers all major components including the compressor, heat exchangers, and control boards. It does not cover consumable items or damage caused by poor water quality, incorrect installation, or lack of maintenance.

Daikin has a dedicated UK technical support team and a network of service engineers. Spare parts availability is generally excellent, with most common parts available for delivery within 24 to 48 hours.

Pricing

Daikin Altherma heat pump unit prices (before installation) typically range from:

  • 4 to 6kW models: £3,500 to £4,500
  • 8 to 10kW models: £4,500 to £5,500
  • 12 to 16kW models: £5,500 to £6,500

Total installed costs (including the outdoor unit, indoor cylinder, controls, pipework, electrical work, and commissioning) typically range from £8,000 to £14,000 depending on property size, complexity, and whether radiator upgrades or other modifications are needed.

After the Boiler Upgrade Scheme grant of up to £7,500, many homeowners pay between £2,000 and £7,000 out of pocket for a fully installed Daikin system.

Daikin vs Competitors

Daikin vs Mitsubishi Ecodan

Both are well-established Japanese brands with strong UK presence. Daikin typically achieves slightly higher SCOP figures and lower noise levels. Mitsubishi Ecodan has a larger installed base in the UK and arguably more extensive spares and service support. Both are excellent choices.

Daikin vs Vaillant Arotherm

Vaillant's Arotherm Plus uses R290 refrigerant (lower environmental impact) and can reach higher flow temperatures (75°C vs 55/70°C). Daikin is typically quieter and has a broader range of models. Vaillant has the advantage of its enormous UK boiler installer network.

Daikin vs Samsung EHS

Samsung is typically more affordable than Daikin and achieves very quiet noise levels. Daikin has a stronger track record and more extensive UK installer network. Samsung represents excellent value, while Daikin offers proven reliability.

Pros and Cons Summary

Pros

  • Excellent SCOP figures — among the highest on the market
  • Very quiet operation, particularly smaller models
  • Strong UK installer network with D1 partner programme
  • Proven reliability backed by decades of heat pump manufacturing
  • Good smart controls and app-based monitoring
  • Monobloc design simplifies installation
  • Up to 10-year extended warranty available
  • Wide range of models from 4kW to 16kW covering most domestic needs

Cons

  • Still uses R32 refrigerant — not yet transitioned to R290 across the full domestic range
  • Pricing is mid-to-upper range — not the cheapest option
  • Low-temperature models limited to 55°C max flow temperature — may not suit older properties without radiator upgrades
  • The ONECTA app, while functional, lacks the detailed energy monitoring some users want

Who Is Daikin Best Suited For?

Daikin is an excellent choice for homeowners who want a reliable, efficient heat pump from a well-established manufacturer with strong UK support. It is particularly well-suited to:

  • Well-insulated homes where low flow temperatures (35 to 45°C) are achievable
  • Properties where noise is a concern (close neighbours, bedroom windows near the unit)
  • Homeowners who value a long warranty and good after-sales support
  • New installations where the monobloc design simplifies the process

For older, poorly insulated properties that need high flow temperatures, the Daikin Altherma 3 H HT model is available but faces strong competition from the Vaillant Arotherm Plus (which reaches 75°C) and Bosch Compress 7400i in this segment.

Frequently Asked Questions

Is Daikin a good heat pump brand?

Yes. Daikin is one of the most respected heat pump manufacturers globally, with decades of experience and a strong track record in the UK. The Altherma 3 range consistently achieves excellent efficiency figures and low noise levels.

How much does a Daikin heat pump cost to install in the UK?

Total installed costs typically range from £8,000 to £14,000 before the Boiler Upgrade Scheme grant. After the grant (up to £7,500), homeowners typically pay £2,000 to £7,000 out of pocket.

What is the COP of a Daikin Altherma 3?

The manufacturer-rated SCOP is up to 4.64 at 35°C flow temperature. Real-world seasonal COP in UK homes is typically 3.2 to 3.8 at low flow temperatures and 2.6 to 3.2 at higher flow temperatures.

How noisy is a Daikin heat pump?

The Altherma 3 produces 37 to 46dB at one metre, depending on the model and output level. At partial load (which is most of the time), noise levels are lower still. 37dB is quieter than a typical library.

What warranty does Daikin offer?

5 years standard, extendable to up to 10 years through a Daikin D1 partner installer. The extended warranty covers all major components.

Does Daikin use R290 refrigerant?

Daikin has R290 models in development and available in some markets, but the UK domestic range currently uses R32 refrigerant. R32 has a lower GWP than the older R410A but is not as environmentally friendly as R290. Check with your installer for the latest model availability.