Switch Together Blog

Types of Heat Pumps (2025)

Written by Mathew Williams | Aug 6, 2025 2:37:55 PM

Thinking about moving away from expensive gas or oil to something greener and more efficient? Heat pumps are increasingly the UK’s go-to solution. But with a few different types on the market — each with their own strengths — how do you know which will actually work best for your home?

This guide covers the main heat pump types, offers an honest look at real-world performance, highlights top-rated models for 2025, and helps you match technology to your property.

 

Types of Heat Pumps

 
 

Type

 

Heat Source

How It Works

 

Best For

 

Typical Efficiency (%)

 

Air Source (ASHP)

Outdoor air

Pulls warmth from the air outside

Most UK homes

300–350% (up to 540% in top models)

Ground Source (GSHP)

Shallow ground

Collects heat from pipes buried underground

Homes with garden space

350–450%

Water-source (WSHP)

Lake/river water

Uses a nearby river, lake, or pond

Homes near open water

400–500%

Hybrid

 

Combines a heat pump and a gas or oil boiler

Homes needing flexibility

Typically ~350–420%+

 (COP = Coefficient of Performance; seasonal CoPs may differ.)
 
 
 
 
 

Air source heat pumps are simple to install and work well for most homes in the UK.

They come in two main types:

  • Air-to-Water: Provides heating and hot water using your radiators or underfloor pipes. This is the type supported by government grants like the Boiler Upgrade Scheme (BUS) (Ofgem, GOV.UK).

  • Air-to-Air: Blows warmed air into your rooms, similar to a reverse air conditioner, but doesn’t heat water. Not covered by current grants (Ofgem).

Air Source Heat Pump Types

 
 
 

Type

 

Description

 

Air-to-Water

Transfers heat into a water-based heating system (radiators, underfloor heating, hot water).

Air-to-Air

Delivers heat as warm air into your home via fans. Does not heat water; less common in the UK.

 
 
 

Why pick air source?
Lower upfront cost than other heat pump types, straightforward installation, and it works for most homes without major modifications.

Air-to-water systems integrate well with existing central heating infrastructure, including radiators and underfloor heating systems. The systems typically operate at lower flow temperatures (35-55°C) compared to gas boilers (60-75°C), requiring longer running times but providing more consistent, comfortable heating.

Housing Compatibility

Suitability for Air-to-Water Systems:

  • Excellent fit (30% of homes): Well-insulated properties with underfloor heating or oversized radiators

  • Good fit with upgrades (40% of homes): Properties requiring radiator replacement or supplementation

 

Ground Source Heat Pumps

These extract warmth from underground using a pipe loop buried in your garden.

  • Suit homes with enough outdoor space for digging.

  • Higher installation cost, but often even lower running costs over time.

Water Source Heat Pumps

Only practical if you have direct access to a river, large pond or lake. Rare, but very efficient where possible.

Hybrid Heat Pumps

A hybrid runs a heat pump alongside your current boiler, switching between them for efficiency and extra warmth on very cold days.

  • Good choice if you want to phase out your old boiler gradually or have high hot water needs.

 

Top Heat Pump Models and Brands in 2025

 

Air Source

 
  

Manufacturer / Brand

Country of Origin

Key Series / Models

Type & Features

Max CoP / SCOP

Notable Points

Panasonic

Japan

Aquarea (L series)

Air-to-water (split & monobloc); also air-to-air Etherea

≈ 5.3

Retrofit‑ready; works with existing radiators

Vaillant

Germany

aroTHERM / aroTHERM plus

Air-to-water

≈ 5.2

Quiet Mark approved; MCS‑certified; hybrid‑ready systems

Daikin

Japan

Altherma (incl. high-temp)

Air-to-water (split & monobloc)

≈ 5.43

R32 refrigerant, inverter tech; works to –28 °C

NIBE

Sweden

F2040, F2120

Air-to-water

≈ 5.0

Cascade-compatible; strong seasonal efficiency

Samsung

South Korea

EHS

Air-to-water (split & monobloc)

Competitive pricing; flexible installation

Mitsubishi Electric

Japan / UK operations

Ecodan

Air-to-water

Widely used in UK; integrates with indoor cylinders

Bosch (Worcester Bosch)

Germany (UK subsidiary)

Compress (e.g. 7000i AW)

Air-to-water

Integrates with Bosch boilers

Hitachi

Japan

Yutaki

Air-to-water

≈ 5.25

High-temp options; multiple capacities

Viessmann

Germany

Vitocal series

Air-to-water (reversible); cascade options

Uses R290; co-gen & cascade-capable units

Baxi (BDR Thermea group)

UK-based (via Spain plant)

Auriga (R32 medium‑temp); Auriga HP+ (R290 high‑temp)

Air-to-water monobloc with hybrid/cascade compatibility

SCOP up to 4.83 at W35; Auriga HP+ up to 5.17 at W35; ~3.96 at W55

Operates to –20 °C; delivers up to 80 °C flow; low‑GWP refrigerants; remote-monitoring, hybrid controls.

 
 
 

 Ground Source

 

Manufacturer / Brand

Origin / Notes

Example Product / Series

Specialisation / Key Points

Kensa Heat Pumps

UK-based

Shoebox series

Compact installations: vertical and hybrid GSHPs

Landy (TT Pumps)

UK (part of TT Pumps)

Ground-source heat pumps

Clivet

Italy-based Europe-wide

Residential and commercial GSHP systems

Viessmann

Germany

geoTHERM series

High-efficiency residential GSHPs

Worcester Bosch

UK (Bosch Group)

Greensource

Domestic GSHP solutions

Mitsubishi Electric

Japan / UK operations

Ecodan (ground variant)

GSHPs for domestic/commercial use

NIBE

Sweden

NIBE Ground

Broad GSHP portfolio

Grant

UK / Ireland

GSHP models & hybrid GSHP/boiler systems

Vaillant

Germany

GSHP models and hybrid GSHP systems

Baxi (BDR Thermea Group)

UK-based brand within European BDR Thermea Group

Auriga Eco/Hybrid Auriga Eco Kit

Hybrid-ready systems combining air-source pumps and boilers