How do heat pumps work in the UK?

Published on 22 Apr 2026

Considering a heat pump for your UK home or business? You're in good company. As the UK moves towards greener energy, more homeowners and small business owners are asking: how do heat pumps work, and are they right for me? These clever devices don't generate heat; they simply move it, offering an energy-efficient way to warm your property and hot water. Let's break down the science, explore their performance in our climate, and see how smart energy management can help you get the most out of them.

Understanding how heat pumps work can help you make informed decisions about your property's energy. With Fuse Energy, you get clear pricing, real-time usage data, 24/7 human customer support, and a modern energy experience designed around you. Switching takes as little as 3 minutes, so you can take control of your bills from day one. Click here to switch to Fuse Energy today and start saving.

Understanding the basics: what is a heat pump and how does it work?

At its core, a heat pump is an ingenious system that transfers thermal energy from one place to another. Think of it like a fridge, but in reverse: instead of moving heat out of a small space, it moves heat into your property. This fundamental principle is what makes them so efficient, often delivering more heat energy than the electrical energy they consume.

The simple science: heat transfer explained

So, how do heat pumps work their magic? They use a refrigerant fluid that cycles through four main stages to absorb heat from a low-temperature source (like the outside air or ground) and release it at a higher temperature indoors.

1. Evaporation: A liquid refrigerant, at a low temperature, flows through an evaporator coil. It absorbs low-grade heat from the external environment, causing it to evaporate and turn into a gas.
2. Compression: The now gaseous refrigerant enters a compressor. This component uses electricity to increase the pressure of the gas, which in turn significantly raises its temperature.
3. Condensation: The hot, high-pressure gas moves into a condenser coil inside your property. Here, it transfers its heat to your heating system (e.g., water for radiators or underfloor heating). As it releases heat, it cools and condenses back into a high-pressure liquid.
4. Expansion: Finally, the high-pressure liquid refrigerant passes through an expansion valve. This reduces its pressure and temperature, ready for it to absorb heat again in the evaporator, repeating the cycle.

This continuous loop is how heat pumps work to keep your space warm.

Air source vs. ground source: key differences for UK properties

When considering how heat pumps work in the UK, you'll primarily encounter two types:

• Air Source Heat Pumps (ASHP): These extract heat from the outside air, even when temperatures drop. They're generally easier and less disruptive to install, making them a popular choice for many UK homes and businesses. How do air source heat pumps work? They simply use a fan to draw in outside air over the evaporator coil.
• Ground Source Heat Pumps (GSHP): These draw heat from the ground via buried pipes. While installation is more complex and costly due to the excavation required, they offer very stable performance as ground temperatures are more consistent than air temperatures. How do ground source heat pumps work? They circulate a fluid through a loop of pipes buried in your garden or under your property.

Both types are designed to operate effectively in our climate, providing efficient heating.

Heat pumps in the UK: performance, efficiency and running costs

Understanding the practicalities of heat pumps in the UK is crucial for homeowners and small business owners.

Cold weather performance, CoP, and property suitability

A common question is: how do heat pumps work in winter, especially in the UK's colder months? Modern heat pumps are designed to perform reliably even when temperatures drop below freezing, making them well-suited to the UK's colder months. While they extract heat from the air, they don't rely on warm air to function, thanks to refrigerants that can absorb heat at very low temperatures, they continue to operate effectively in cold conditions. Efficiency is measured by the Coefficient of Performance (CoP)1, which shows how many units of heat are produced per unit of electricity consumed. Although CoP may decrease slightly in colder weather, heat pumps can still deliver more heat energy than the electricity they use, for example, a CoP of 3 means 3kWh of heat for every 1kWh of electricity. Higher CoP values indicate greater efficiency and lower running costs.

For optimal performance, property suitability is key. Good insulation, double glazing, and an appropriate heating distribution system (like larger radiators or underfloor heating) are essential to maximise efficiency and keep those running costs down.

Benefits, environmental impact, and government grants

The benefits of heat pumps are significant. They offer a substantial reduction in carbon emissions compared to traditional gas or oil boilers, aligning with the UK's net-zero targets2. This environmental advantage, coupled with lower running costs (when optimised), makes them an attractive investment.

To support their adoption, the UK government offers incentives like the Boiler Upgrade Scheme (BUS), providing grants to help homeowners and small businesses with the upfront installation costs3. This makes the transition to a heat pump more accessible.

Powering your heat pump with Fuse Energy: smart monitoring for smarter savings

Heat pumps are significant electricity consumers, so understanding and managing their energy usage is vital for cost-effectiveness. This is where Fuse Energy comes in.

Fuse Energy installs Vaillant aroTHERM plus heat pumps, and we are MCS and TrustMark certified. We handle planning approvals, DNO applications, paperwork, installation, and final checks, and are certified to provide a BUS grant. Our smart meters provide accurate, real-time, half-hourly consumption data. This granular insight allows you to see exactly how much electricity your heat pump is using, helping you identify usage patterns and optimise its operation.

Our clear, transparent billing, issued on a calendar-month basis, makes it easy to track your energy expenditure. Detailed breakdowns on your bill help you understand your overall energy costs, allowing you to see the impact of your usage patterns. By leveraging this precise consumption data, you can make informed decisions about how and when you run your system, potentially reducing running costs and enhancing the return on your heat pump investment. Fuse Energy provides the essential tools and information you need to monitor, understand, and ultimately control your energy consumption, ensuring you reap the full financial and environmental benefits of your heat pump.

Managing your energy bills should be clear and easy to understand. Fuse Energy focuses on straightforward pricing, so you can see exactly what you're paying without unnecessary complexity. If you have a smart meter, you can view detailed usage data through the app or website, helping you understand how you can lower your bills. Our 24/7 human support team is always on hand with fast response times whenever you need help. Click here to switch to Fuse Energy in as little as 3 minutes. Find out about our mission by clicking here.

References

1. Energy Saving Trust. Heat pumps: how they work, costs and savings
2. GOV.UK. Heat and buildings strategy
3. Ofgem. Boiler Upgrade Scheme (BUS)