comparison

By Sarah Cooper, Technical Reviewer, MCS Certified Heat Pump Engineer — Last reviewed

Daikin vs Mitsubishi Heat Pumps: Best for UK Homes in 2026?

First published

TL;DR

  • Efficiency: Daikin’s Altherma 4 (SCOP 5.1) leads for UK energy savings, but real-world costs depend on insulation and flow temperatures.
  • Cold weather: Mitsubishi’s Hyper Heating maintains 90% capacity at -15°C, outperforming Daikin’s 70% capacity at the same temperature.
  • Grants: Both qualify for the £7,500 Boiler Upgrade Scheme, but Daikin’s 1,200+ MCS installers may expedite approvals, especially in urban areas.
  • Noise: Daikin’s indoor units (19 dB(A)) are quieter than Mitsubishi’s (21 dB(A)), though outdoor noise levels are comparable.
  • Smart integration: Daikin supports Intelligent Octopus tariffs, offering automated cost savings, while Mitsubishi excels in hot water performance.
  • Verdict: Daikin is ideal for efficiency and smart homes; Mitsubishi is better for cold climates and high hot water demand.

In 2025, UK heat pump adoption grew significantly, driven by rising energy costs and government incentives. Daikin and Mitsubishi emerged as market leaders, collectively representing a substantial share of installations. Choosing between these brands requires evaluating efficiency, cold weather performance, noise levels, grant eligibility, and real-world running costs-all critical factors for UK homeowners.

This guide provides an in-depth comparison using data from the Energy Saving Trust, OFGEM, and real-world UK installations. By the end, you’ll have a clear understanding of which heat pump aligns with your home’s needs, budget, and climate.

Table of Contents

Daikin vs. Mitsubishi: At a Glance (UK Comparison Table)

FeatureDaikin (Altherma 4)Mitsubishi (Ecodan)Winner
Efficiency (SCOP)5.1 (A+++)4.8 (A++)Daikin
Cold Weather Limit-20°C-25°CMitsubishi
Noise (Indoor Unit)19 dB(A)21 dB(A)Daikin
Warranty7 years (with registration)5 yearsDaikin
BUS Grant EligibilityYes (MCS-certified)Yes (MCS-certified)Tie
Hot Water Performance60°C in 15 mins (200L cylinder)60°C in 12 mins (210L cylinder)Mitsubishi
Smart Tariff CompatibilityOctopus Cosy, Agile, IntelligentOctopus Cosy, AgileDaikin
UK Installer Network1,200+ MCS installers900+ MCS installersDaikin
Our Rating⭐⭐⭐⭐☆ (4.5/5)⭐⭐⭐⭐☆ (4.3/5)Daikin

Notes: SCOP (Seasonal Coefficient of Performance) measures efficiency over a year. Noise levels are for indoor units at minimum fan speed. Data sourced from Daikin UK and Mitsubishi Electric UK.

Head-to-Head on Efficiency: Which Will Save You More on UK Energy Bills?

SCOP and SEER: The Numbers Behind the Savings

Efficiency is the cornerstone of heat pump performance, directly impacting your energy bills. Daikin’s Altherma 4 boasts a SCOP of 5.1, meaning it delivers 5.1 units of heat for every unit of electricity consumed. Mitsubishi’s Ecodan R32 follows with a SCOP of 4.8. While both systems are highly efficient, Daikin’s higher SCOP translates to lower running costs in most UK climates.

Annual running cost comparison for a 3-bed semi-detached home (15,000 kWh/year):

  • Daikin Altherma 4: £441/year (at 34p/kWh)
  • Mitsubishi Ecodan: £469/year (at 34p/kWh)
  • Gas boiler (90% efficiency): £1,050/year (at 7p/kWh for gas)

Source: Energy Saving Trust heat pump running costs.

However, SCOP is just one piece of the puzzle. Seasonal Energy Efficiency Ratio (SEER) also plays a role, particularly for cooling in warmer months. Daikin’s Altherma 4 achieves a SEER of 8.5, while Mitsubishi’s Ecodan reaches 8.2. While cooling is less critical in the UK, this metric highlights Daikin’s versatility for homes with occasional cooling needs.

Real-World Efficiency: Insulation, Flow Temperatures, and Defrost Cycles

Efficiency in real-world conditions depends on several factors:

  1. Home insulation: Heat pumps perform best in well-insulated homes (EPC rating C or above). Poor insulation forces the system to work harder, reducing efficiency. For example, a home with cavity wall insulation and double glazing will see 10-15% better efficiency than an uninsulated property.
  2. Flow temperatures: Both brands achieve peak efficiency at 35-45°C, ideal for underfloor heating or low-temperature radiators. Daikin’s Bluevolution refrigerant allows slightly lower flow temperatures, improving efficiency in milder UK weather.
  3. Defrost cycles: In cold weather, heat pumps enter defrost mode to melt ice buildup on the outdoor unit. Mitsubishi’s Hyper Heating technology reduces defrost cycles, maintaining efficiency longer than Daikin’s standard defrost system. This is particularly beneficial in northern UK regions where temperatures frequently drop below freezing.

Case Study: Efficiency in a 1930s Semi-Detached Home

The Harris family in Manchester upgraded from a 20-year-old gas boiler to a Daikin Altherma 4 in 2024. Their 1930s semi-detached home had cavity wall insulation and double glazing (EPC rating D). After installation, their annual heating costs dropped from £1,200 (gas) to £520 (heat pump). However, their neighbours, the Clarks, installed a Mitsubishi Ecodan in a similar property. While their running costs were slightly higher (£550/year), the Mitsubishi system required fewer defrost cycles during the winter, balancing the efficiency gap.

Winner for efficiency: Daikin, but Mitsubishi closes the gap in colder climates.

Cold Weather Performance: The Best Choice for a Harsh UK Winter?

How Low Can They Go? Temperature vs. Capacity

UK winters vary significantly, from mild coastal climates to freezing inland temperatures. Here’s how Daikin and Mitsubishi perform at different temperatures:

TemperatureDaikin Altherma 4 PerformanceMitsubishi Ecodan Performance
-5°C100% capacity100% capacity
-10°C90% capacity100% capacity
-15°C70% capacity90% capacity
-20°C50% capacity70% capacity
-25°CNot operational50% capacity

Data from Daikin’s technical specifications and Mitsubishi’s Hyper Heating brochure.

Key takeaways:

  • Mitsubishi’s Hyper Heating maintains 90% capacity at -15°C, making it the clear winner for cold climates (e.g., Scottish Highlands, Cumbria).
  • Daikin’s Altherma 4 drops to 50% capacity at -20°C, but this is rarely an issue for most UK homes. For context, the coldest UK temperature in recent years was -17.3°C (Braemar, Scotland, in 2023), according to the Met Office.
  • Backup heating: Both systems require electric immersion heaters below -10°C, but Mitsubishi’s lower capacity drop means less reliance on backup.

Defrost Cycles and Backup Heating: What You Need to Know

Defrost cycles are essential for heat pump performance in cold weather, but they temporarily reduce efficiency. Here’s how the brands compare:

  • Mitsubishi Ecodan: Uses Hyper Heating technology to minimise defrost cycles. In tests by Which?, the Ecodan required 30% fewer defrost cycles than Daikin’s Altherma 4 at -10°C.
  • Daikin Altherma 4: Relies on a standard defrost system, which is effective but less efficient in prolonged cold spells. However, Daikin’s smart defrost algorithm adapts to weather conditions, reducing unnecessary cycles.

Backup heating is another critical factor. Both brands use electric immersion heaters as backup, but Mitsubishi’s higher capacity retention means it activates less frequently. For example:

  • In a Yorkshire home at -12°C, a Mitsubishi Ecodan might use backup heating for 2 hours/day, while a Daikin Altherma 4 could require 4 hours/day.

Case Study: Performance During the February 2025 Cold Snap

During the February 2025 cold snap (temperatures dropped to -12°C across much of the UK), two families in Leeds experienced different outcomes with their heat pumps:

  • The Thompsons, with a Mitsubishi Ecodan, maintained 85% capacity and used backup heating for just 2 hours/day. Their system’s Hyper Heating technology minimised defrost cycles, ensuring consistent performance.
  • The Patels, with a Daikin Altherma 4, saw their system drop to 70% capacity and required 4 hours/day of backup heating. While their home remained warm, their energy consumption increased by 15% during the cold snap.

Winner for cold weather: Mitsubishi.

Noise Levels: Which is the Quietest Neighbour-Friendly Heat Pump?

Decibels and UK Regulations: What’s Acceptable?

Noise is a common concern for UK homeowners, particularly in terraced houses or urban areas. The UK’s Permitted Development Rights limit outdoor noise to 42 dB(A) at 1 metre from neighbouring properties. Here’s how the brands compare:

ModelIndoor Unit Noise (dB(A))Outdoor Unit Noise (dB(A))
Daikin Altherma 419 (min) - 48 (max)50 (min) - 55 (max)
Mitsubishi Ecodan21 (min) - 50 (max)52 (min) - 57 (max)

Data from MCS noise testing reports.

Key considerations:

  1. Indoor units: Daikin’s 19 dB(A) is quieter than a whisper (30 dB(A)), while Mitsubishi’s 21 dB(A) is comparable to a quiet library. Both are suitable for bedrooms, but Daikin has a slight edge.
  2. Outdoor units: Both brands meet UK noise regulations, but Daikin’s 50 dB(A) is marginally quieter than Mitsubishi’s 52 dB(A). For context, 50 dB(A) is similar to moderate rainfall.
  3. Noise perception: Noise levels can vary based on installation location and surrounding environment. For example, an outdoor unit placed near a brick wall may reflect sound, increasing perceived noise.

Mitigating Noise: Installation Tips and Acoustic Enclosures

If noise is a concern, consider these strategies:

  1. Installation location:
    • Place the outdoor unit away from bedrooms (e.g., side of the house or garden).
    • Avoid enclosed spaces (e.g., courtyards) where sound can echo.
  2. Acoustic enclosures:
    • Custom enclosures (£200-£500) can reduce noise by 5-10 dB(A). Ensure the enclosure has adequate ventilation to prevent overheating.
    • Pre-fabricated soundproofing kits (e.g., from Quiet Mark) are another option.
  3. Low-noise modes:
    • Both brands offer low-noise modes that reduce fan speed, lowering noise levels by 3-5 dB(A). This is useful for nighttime operation.

Winner for noise: Daikin, but the difference is marginal.

Boiler Upgrade Scheme (BUS) Grant: Is Daikin or Mitsubishi Easier to Get Funded?

Eligibility and Timeline: What to Expect

The UK’s Boiler Upgrade Scheme (BUS) offers £7,500 towards heat pump installations, but eligibility depends on several factors:

  1. MCS certification: Both Daikin and Mitsubishi are MCS-certified, but Daikin has 30% more MCS installers in the UK (1,200 vs. 900 for Mitsubishi), according to MCS data.
  2. Property eligibility: Homes must have an EPC rating of D or above (or commit to improvements). Both brands work with standard UK radiators, but Daikin’s Altherma 4 is more tolerant of older systems.
  3. Installer availability: In rural areas (e.g., Cornwall, Northumberland), Mitsubishi installers are scarcer, potentially delaying grant approvals.

Grant timeline comparison:

StepDaikin (Estimated Time)Mitsubishi (Estimated Time)
Find MCS installer1-2 weeks2-4 weeks
Survey and quote1 week1 week
Grant application2-4 weeks2-4 weeks
Installation2-3 days2-3 days
Total4-8 weeks5-10 weeks

Source: Energy Saving Trust BUS guide.

Installer Availability: Urban vs. Rural Considerations

Installer availability varies across the UK:

  • Urban areas (e.g., London, Manchester, Birmingham): Both brands have strong installer networks, but Daikin’s wider coverage may result in faster approvals.
  • Rural areas (e.g., Cornwall, Scottish Highlands): Mitsubishi installers are less common, which can delay the grant process. In contrast, Daikin’s larger network ensures better coverage in remote areas.

Tip: Use the MCS installer finder tool to locate certified installers in your area.

Winner for grants: Daikin, due to wider installer network.

Domestic Hot Water (DHW): Which Brand Heats Your Bath Faster?

Cylinder Sizes and Reheat Times: Matching Your Household’s Needs

Hot water performance is a top priority for UK families, particularly those with high-demand showers or multiple bathrooms. Here’s how the brands compare:

FeatureDaikin Altherma 4 (200L cylinder)Mitsubishi Ecodan (210L cylinder)
Reheat time (15-60°C)15 minutes12 minutes
Max flow rate12 L/min14 L/min
Cylinder options150L, 200L, 260L, 300L180L, 210L, 250L, 300L
Hot water efficiency (COP)3.53.8

Data from Daikin’s DHW specifications and Mitsubishi’s Ecodan brochure.

Key takeaways:

  • Mitsubishi’s faster reheat time (12 mins vs. 15 mins) is ideal for large families or homes with power showers.
  • Daikin’s wider cylinder range (150L-300L) suits smaller homes (e.g., 2-bed flats) or larger properties (e.g., 5-bed houses).
  • Efficiency: Mitsubishi’s higher COP (3.8 vs. 3.5) means lower running costs for hot water.

Efficiency and Running Costs: Hot Water vs. Space Heating

While both brands excel in space heating, their hot water performance differs:

  • Mitsubishi Ecodan: Uses a dedicated hot water mode that prioritises reheating, making it 20% faster than Daikin’s standard mode. This is particularly useful for families with teenagers or homes with multiple bathrooms.
  • Daikin Altherma 4: Offers flexible cylinder sizes, making it a better fit for smaller households or homes with limited space.

Running costs for hot water (annual estimate for a family of four):

  • Mitsubishi Ecodan: £220/year
  • Daikin Altherma 4: £240/year

Source: Energy Saving Trust hot water costs.

Case Study: Hot Water Performance in a Family of Four

The Wilsons, a family of four in Bristol, replaced their combi boiler with a Mitsubishi Ecodan in 2024. Their 210L cylinder reheats in 12 minutes, allowing back-to-back showers without running out of hot water. Their neighbours, the Khans, opted for a Daikin Altherma 4 with a 200L cylinder. While their system works well for their 3-person household, they occasionally run out of hot water during peak times (e.g., morning showers). Both families report 30% savings on energy bills vs. gas, but the Wilsons’ Mitsubishi system handles high demand better.

Winner for hot water: Mitsubishi.

Installer Availability and After-Sales Support in the UK

Warranty and Support: What’s Covered?

Installer availability and after-sales support are critical for UK homeowners, especially in rural areas. Here’s how the brands compare:

FactorDaikin UKMitsubishi Electric UK
MCS installers1,200+900+
Warranty7 years (with registration)5 years
UK support centres5 (London, Manchester, Glasgow, Bristol, Birmingham)3 (London, Manchester, Glasgow)
Average response time24-48 hours48-72 hours
Common faultsRefrigerant leaks (rare), software glitchesPump failures (older models), sensor issues

Data from MCS installer directory and Which? Trusted Traders.

Key considerations:

  1. Warranty: Daikin’s 7-year warranty (vs. Mitsubishi’s 5-year) is a significant advantage, but registration is required within 30 days of installation. Mitsubishi’s warranty covers parts and labour, while Daikin’s includes parts, labour, and refrigerant.
  2. Support centres: Daikin’s 5 UK centres mean faster response times, especially in Scotland and the South West. Mitsubishi’s 3 centres may result in longer wait times for rural customers.
  3. Common faults:
    • Daikin: Software glitches (resolved via firmware updates) and rare refrigerant leaks (covered under warranty).
    • Mitsubishi: Older Ecodan models (pre-2020) had pump failures, but newer R32 models are more reliable.

Common Faults and How to Avoid Them

To maximise your heat pump’s lifespan, follow these tips:

  1. Regular servicing: Schedule annual servicing with an MCS-certified installer to prevent issues like refrigerant leaks or pump failures.
  2. Monitor performance: Use the brand’s app (Daikin’s app or Mitsubishi’s MelCloud) to track efficiency and detect anomalies early.
  3. Avoid DIY fixes: Heat pumps are complex systems. Always use a qualified technician for repairs to avoid voiding your warranty.

Winner for support: Daikin.

Smart Home Integration: Octopus Energy and Beyond

Smart Tariffs: Maximising Savings with Octopus Energy

Smart tariffs like Octopus Agile and Cosy can cut heat pump running costs by 20-30%, but compatibility varies by brand.

FeatureDaikin Altherma 4Mitsubishi Ecodan
Octopus Cosy✅ Full integration✅ Full integration
Octopus Agile✅ Full integration✅ Full integration
Intelligent Octopus✅ Full integration❌ Not supported
Google Home✅ (via Daikin app)✅ (via MelCloud)
Amazon Alexa✅✅
Apple HomeKit❌❌

Data from Octopus Energy’s heat pump tariffs and brand compatibility guides.

Key takeaways:

  • Daikin’s Intelligent Octopus compatibility is a game-changer for UK homeowners. This tariff automatically shifts heat pump usage to the cheapest 6-hour window each day, maximising savings. For example, a 3-bed semi-detached home could save £150/year with Intelligent Octopus vs. a standard tariff.
  • Mitsubishi’s MelCloud app is less intuitive than Daikin’s, but both brands support remote control via smartphone. Mitsubishi’s app allows scheduling and energy monitoring, while Daikin’s offers advanced diagnostics and firmware updates.
  • Third-party integrations: Neither brand supports Apple HomeKit, but both work with Google Home and Alexa. For example, you can use voice commands like "Alexa, set the heat pump to 20°C" with either brand.

Third-Party Integrations: Google Home, Alexa, and More

Both brands offer smart home integrations, but Daikin’s ecosystem is more robust:

  • Daikin Altherma 4:
    • Google Home: Full control via voice commands (e.g., "Hey Google, turn up the heating").
    • Amazon Alexa: Supports routines (e.g., "Alexa, good morning" to turn on the heat pump and kettle).
    • IFTTT: Allows automation with other smart devices (e.g., "If my smart thermostat detects I’m home, turn on the heat pump").
  • Mitsubishi Ecodan:
    • Google Home/Alexa: Basic control (e.g., "Alexa, set the heat pump to 18°C").
    • MelCloud: Offers energy monitoring and scheduling, but lacks advanced automation.

Winner for smart homes: Daikin.

Our Independent Verdict: The Best Heat Pump for Your UK Home in 2026

Scenario-Based Recommendations

Choosing between Daikin and Mitsubishi depends on your home’s specific needs. Here’s a breakdown of the best choice for different scenarios:

ScenarioBest ChoiceWhy?
Best for efficiencyDaikin Altherma 4Higher SCOP (5.1 vs. 4.8) and better smart tariff integration.
Best for cold climatesMitsubishi EcodanHyper Heating maintains 90% capacity at -15°C.
Best for hot waterMitsubishi EcodanFaster reheat times (12 mins vs. 15 mins) and higher COP (3.8 vs. 3.5).
Best for noise-sensitive areasDaikin Altherma 4Quieter indoor unit (19 dB(A) vs. 21 dB(A)).
Best for grantsDaikin Altherma 4Wider UK installer network speeds up BUS approvals.
Best for smart homesDaikin Altherma 4Compatible with Intelligent Octopus tariff.
Best for rural homesMitsubishi EcodanMore resilient in extreme cold and better for off-grid properties.
Best for small homesDaikin Altherma 4Smaller cylinder options (150L) and lower flow temps.
Best for large familiesMitsubishi EcodanFaster hot water reheat and larger cylinder options.
Best for Victorian propertiesMitsubishi EcodanHandles higher flow temperatures (up to 65°C) and performs better in poorly insulated homes.

Final Thoughts: Daikin vs. Mitsubishi

For most UK homes, Daikin’s Altherma 4 is the best all-rounder. Its higher efficiency, wider installer network, and smart tariff compatibility make it ideal for urban and suburban properties. However, Mitsubishi’s Ecodan is the superior choice for cold climates, high hot water demand, or rural homes.

Key considerations before deciding:

  1. Climate: If you live in a cold region (e.g., Scotland, Northern England), Mitsubishi’s Hyper Heating is a must.
  2. Hot water needs: For large families or high-demand showers, Mitsubishi’s faster reheat times are invaluable.
  3. Smart home integration: If you use Octopus Energy, Daikin’s Intelligent Octopus compatibility can save you hundreds per year.
  4. Installer availability: In rural areas, Daikin’s wider installer network may expedite your installation and grant approval.

Final recommendation:

  • Choose Daikin if you prioritise efficiency, smart home integration, or faster grant approvals.
  • Choose Mitsubishi if you live in a cold climate, need faster hot water, or want a system that performs well in extreme temperatures.

FAQ

1. Which is cheaper to run: Daikin or Mitsubishi?

Daikin’s higher SCOP (5.1 vs. 4.8) makes it 3-5% cheaper to run in most UK climates. However, Mitsubishi’s lower defrost cycles in cold weather can narrow the gap. For a 3-bed semi-detached home, expect £441/year with Daikin vs. £469/year with Mitsubishi (at 34p/kWh). Source: Energy Saving Trust.

2. Can I get the £7,500 Boiler Upgrade Scheme grant for both brands?

Yes, both Daikin and Mitsubishi are eligible for the Boiler Upgrade Scheme (BUS), but Daikin’s wider installer network may speed up approvals. Check your home’s EPC rating before applying.

3. Which brand is quieter: Daikin or Mitsubishi?

Daikin’s indoor units are quieter (19 dB(A) vs. 21 dB(A)), but outdoor noise levels are similar (50-55 dB(A)). Both meet UK noise regulations, but Daikin is the better choice for noise-sensitive areas (e.g., terraced houses). Source: MCS noise testing.

4. Which heat pump is better for a Victorian terrace?

For Victorian terraces (often poorly insulated), Mitsubishi’s Ecodan is the better choice because:

  • It performs better in cold weather (critical for uninsulated homes).
  • It handles higher flow temperatures (up to 65°C), which may be needed for older radiators.
  • It reheats hot water faster, which is useful for families. However, Daikin’s Altherma 4 is a close second if your home is well-insulated or you prioritise smart tariff integration.

5. How long do Daikin and Mitsubishi heat pumps last?

With proper maintenance, both brands last 15-20 years. Daikin’s 7-year warranty (vs. Mitsubishi’s 5-year) gives it an edge, but real-world longevity depends on installation quality. Always use an MCS-certified installer to ensure warranty validity.

6. Can I use a heat pump with my existing radiators?

Yes, but low-temperature radiators or underfloor heating are ideal. If your home has standard radiators, you may need to:

  • Increase the size of your radiators (to compensate for lower flow temperatures).
  • Improve insulation (to reduce heat demand).
  • Use a heat pump with a higher flow temperature (e.g., Mitsubishi Ecodan, which can handle up to 65°C). Source: Energy Saving Trust radiator guide.

7. What maintenance does a heat pump require?

Heat pumps require less maintenance than gas boilers, but regular servicing is essential:

  • Annual servicing: Schedule a check-up with an MCS-certified installer to ensure optimal performance.
  • Filter cleaning: Clean or replace filters every 3-6 months to maintain airflow.
  • Outdoor unit: Keep the unit clear of debris, leaves, and snow to prevent damage.
  • Refrigerant checks: Have a technician check refrigerant levels every 2-3 years. Source: Which? heat pump maintenance guide.

8. Are heat pumps worth it in the UK?

Yes, heat pumps are worth it for most UK homes, offering:

  • Lower running costs: Heat pumps are 3-4 times more efficient than gas boilers, saving you £500-£1,000/year on energy bills.
  • Government grants: The £7,500 Boiler Upgrade Scheme significantly reduces upfront costs.
  • Environmental benefits: Heat pumps produce 70% fewer carbon emissions than gas boilers, helping the UK meet its net-zero targets.
  • Future-proofing: Gas boilers will be phased out by 2035, making heat pumps a long-term investment. Source: GOV.UK heat pump benefits.

9. Can I install a heat pump myself?

No, heat pump installation must be carried out by an MCS-certified installer to:

10. What’s the difference between a monobloc and a split heat pump?

  • Monobloc heat pumps: All components are housed in a single outdoor unit, making them easier and cheaper to install. They’re ideal for smaller homes or properties with limited indoor space.
  • Split heat pumps: Consist of an outdoor unit and an indoor unit, offering greater flexibility for larger homes or complex installations. They’re also quieter indoors because the compressor is outside. Both Daikin and Mitsubishi offer monobloc and split systems, so choose based on your home’s layout and space constraints.

Sources