Understanding air source heat pumps

How air source heat pumps work

Air source heat pumps take heat from the outdoor air and use it to warm your home and hot water.

They run on electricity, are highly efficient, and work well with radiators, underfloor heating, and modern insulation.

Why heat pump efficiency matters

The efficiency of a heat pump is measured using the Seasonal Coefficient of Performance, also known as the Seasonal COP.

A higher rating means lower running costs and better performance through the year.

Why choosing the right model is important

Choosing the right heat pump affects comfort, noise levels, long term costs, and how well it heats your home during winter.

The best systems balance efficiency, reliability, and strong manufacturer support.

The best 5 air source heat pumps for UK homes in 2025

Below is a homeowner friendly list that reflects efficiency, reliability, cold weather performance, and overall value.

1. Mitsubishi Ecodan

Why it stands out

One of the most popular UK choices thanks to strong cold weather performance, low running noise, and excellent long term reliability.

Best for

Most UK homes, including older properties with upgraded radiators.

Key features

• Consistent performance at low outdoor temperatures
  

• Simple controls and reliable hot water production
  

• Wide range of sizes for small and large homes

2. Vaillant aroTHERM plus

Why it stands out

Vaillant’s aroTHERM plus uses natural refrigerant technology and offers excellent efficiency with some of the quietest operation on the market.

Best for

Homes prioritising low running costs and quiet operation.

Key features

• High efficiency across all seasons
  

• Very low noise output
  

• Strong manufacturer reputation and long warranties

3. Samsung EHS Mono

Why it stands out

A cost effective option with good efficiency and strong integration with smart controls.

Best for

Homes looking for strong performance at a more accessible price point.

Key features

• Efficient performance for small and medium homes
  

• Smart control compatibility
  

• Good reliability at lower cost

4. LG Therma V R32

Why it stands out

Popular for high efficiency, modern controls, and consistent output.

Best for

Homes focused on modern features and energy monitoring.

Key features

• High energy efficiency
  

• Quiet running
  

• Good compatibility with underfloor heating

5. Daikin Altherma 3

Why it stands out

Reliable, efficient, and well suited for larger homes needing more heating capacity.

Best for

Homes with higher heat demand or larger hot water needs.

Key features

• Excellent cold weather performance
  

• Strong long term reliability
  

• Good installer support network

Comparison table: Best air source heat pumps 2025

What to consider before choosing a heat pump

Home insulation and heat loss

A heat pump works best when your home retains heat well. Good insulation reduces running costs and improves performance.

Your radiator or underfloor heating system

Heat pumps perform efficiently at lower flow temperatures.

Many homes benefit from slightly larger radiators or underfloor heating for best results.

Hot water demand

Bigger families or homes with multiple bathrooms may benefit from a higher capacity heat pump.

Running costs

Running costs vary based on electricity prices, insulation, and efficiency. High efficiency models reduce long term bills.

Noise levels

Modern heat pumps run quietly, but homeowners should still consider placement such as a side path or garden area.

Choosing the right heat pump for your home

Small homes or flats

Look for compact models with lower outputs, such as Samsung EHS Mono.

Medium homes

Mitsubishi Ecodan or Vaillant aroTHERM plus fit most UK three bed homes well.

Large homes

Daikin Altherma 3 or larger Ecodan units are ideal for higher demand and multiple bathrooms.

iHeat and air source heat pumps

iHeat installs air source heat pumps nationwide using qualified and accredited heating engineers.

Homeowners can get an instant online quote and access 0% APR finance through FCA regulated providers.

All installations include manufacturer warranties and are fitted to current UK standards.

iHeat heat pump benefits at a glance

Choosing the best air source heat pump for 2025

The best air source heat pump for your home depends on budget, property size, insulation, and hot water demand.

Models from Mitsubishi, Vaillant, Samsung, LG, and Daikin all offer strong performance, long warranties, and good seasonal efficiency.

With expert guidance and finance support from iHeat, UK homeowners can install a reliable and efficient heat pump that lowers bills and reduces carbon emissions.