Last Updated on 17 November 2025
A Simple Comparison Of Four High-Performing Models
Choosing a heat pump is easier when you can see the differences side by side.
This guide compares four leading models using only the details from their product pages.
The aim is to give you clear, practical information so you can decide which one fits your home,
your budget and your heating needs.
Quick Overview
| Model | Output | Efficiency | Noise | Key Point |
|---|---|---|---|---|
| Grant Aerona³ 6 kW | 6 kW | A+++ | 54.2 dB at 1 m | Compact and reliable |
| Samsung HT Mono 8 kW | 8 kW | High temp up to 70°C | Very quiet | Strong cold-weather performance |
| Vaillant aroTHERM Plus 7 kW | 7 kW | SCoP up to 5.03 | Quiet | Ideal for modern retrofits |
| Mitsubishi Ecodan 6 kW | 6 kW | A+++ | Ultra quiet | Trusted unit for UK homes |
Price Guide
Heat pump prices vary across brands and retailers.
The figures below help you see the relative cost of each model.
These prices refer to the unit only unless stated.
- Grant Aerona³ 6 kW
Typical unit price around £3,000 to £4,200.
Some installation packages start from £3,150 plus VAT. - Samsung HT Mono 8 kW
Typical unit price around £4,000 to £7,000 depending on the retailer and package.
Higher cost reflects higher output and higher temperature performance. - Vaillant aroTHERM Plus 7 kW
Typical unit price around £4,100 to £4,700. - Mitsubishi Ecodan 6 kW
Typical unit price around £2,900 to £3,800.
Full Installation Costs
A full installation is usually higher than the unit price.
Most UK homes fall into the £8,000 to £12,000 range after the Boiler Upgrade Scheme.
Larger properties or homes with old radiators may pay more.
What Affects Cost
- Size of the home
- Quality of insulation
- Cylinder size
- Radiator upgrades
- Pipework condition
- Outdoor location
- Brand choice
- Installer rates
These points explain why two quotes for the same model can be very different.
The survey stage always matters.
Grant Aerona³ 6 kW
A good match for smaller homes that need strong efficiency without taking up much space.
The Aerona³ has an A+++ rating and a working range from minus 20°C to 43°C.
That gives steady performance in a typical UK winter.
The noise level is 54.2 dB at one metre.
Buyers with close neighbours like having a clear figure to compare.
The unit is compact at 67.5 cm high and 89.8 cm wide.
It also has a 7 year warranty which adds long term reassurance.
Best for
+ Small to medium homes.
+ Limited outdoor space.
+ Owners who want a proven and efficient model.
Samsung HT Mono 8 kW
This model suits homes with higher demand.
It delivers hot water up to 70°C which helps when replacing an older boiler that ran at higher temperatures.
It works in extreme cold down to minus 30°C which gives extra stability during cold snaps.
Samsung notes that the system runs very quietly.
The product package also includes a 170 litre Joule cylinder and a radiator upgrade kit.
That makes it a practical choice for a full system replacement.
Best for
+ Medium to larger homes.
+ Higher hot water use.
+ People who want strong performance in cold weather.
Vaillant aroTHERM Plus 7 kW
A popular option for retrofits.
It reaches a SCoP of up to 5.03.
It also uses R290 refrigerant which has a lower global warming potential.
The system is designed to be quiet and dependable.
The package includes a 150 litre Unistor cylinder.
Vaillant positions this model as a strong choice for people upgrading an existing heating system with less disruption to the rest of the home.
Best for
+ Existing homes moving away from gas or oil.
+ Buyers who want solid energy performance and a trusted brand.
Mitsubishi Ecodan 6 kW Monobloc
A compact monobloc unit built for UK homes.
It has an A+++ rating and works between minus 20°C and 35°C.
The brand highlights ultra quiet operation.
The product listing shows it paired with a 150 litre pre plumbed cylinder which helps reduce installation time.
The simple design appeals to homeowners who want a neat outdoor unit that blends into the property.
Best for
+ Homes where noise is a concern.
+ People who want a reliable model from a well known manufacturer.
How To Choose The Right Heat Pump
Start with the size of your home.
A smaller property usually suits a 6 kW unit like the Grant or Mitsubishi.
A larger home or one with higher hot water demand may need the 7 kW Vaillant or the 8 kW Samsung.
Think about outdoor space.
The Grant has clear dimensions which help when planning placement in a tight garden.
Check noise levels.
If the unit sits near bedrooms or neighbours, models with clear noise data help you weigh up the impact.
Look at your current heating system.
If you are replacing a high-temperature boiler, Samsung’s higher hot water output can reduce the need for radiator upgrades.
If you want a smooth retrofit with minimal disruption, the Vaillant is designed around that.
Consider warranty and brand reputation.
A long warranty or established manufacturer can reduce long term risk.
Final Thoughts
All four heat pumps offer strong performance.
The right choice depends on your home, your heating habits and your priorities.
If you are unsure, a heat loss survey will confirm the correct size and help you match each model to your property.
