What Is a Heat Pump and How Does It Work?
If you’re just starting to explore energy-efficient ways to heat your home, you may have come across the term heat pump and wondered what it actually means. We get questions about this technology all the time, especially from homeowners looking to reduce their energy bills or lower their carbon footprint. Heat pumps have grown in popularity across the UK in recent years, thanks to the focus on greener living, but the way they work can seem a bit confusing at first. The good news is that they’re easier to understand than they sound.
At its core, a heat pump is a system that moves heat rather than generates it. Unlike traditional boilers that burn gas or oil to create warmth, heat pumps simply transfer existing heat from one place to another – either from the air or the ground – and use it to heat your home and water. Because they rely on a small amount of electricity to operate and use renewable sources of heat, they’re considered highly energy-efficient. That makes them a great long-term option for those of us who want to reduce our reliance on fossil fuels without compromising on comfort.
There are two main types of heat pump used in UK homes: air source and ground source. Both systems work on the same basic principles but draw heat from different sources. Let’s break down how each one works and what sort of experience you can expect when using them.
Air Source Heat Pumps: How They Work
Air source heat pumps (ASHPs) extract warmth from the air outside, even when it feels cold. They use a refrigeration cycle – similar to what you’d find in a fridge or air conditioning unit – to absorb and amplify this heat before distributing it indoors. The system has an outdoor unit that draws in air, passes it over a refrigerant fluid, and compresses the fluid to increase its temperature. That heat is then transferred to your central heating system, typically through radiators or underfloor heating.
One thing that surprises many people is how effective these systems are, even in lower temperatures. Modern air source heat pumps can still operate efficiently in UK winters, although they tend to work best in well-insulated homes. According to the Energy Saving Trust, an ASHP can deliver around three times more energy in heat than it uses in electricity, making it around 300% efficient. That’s a big step up from even the best gas boilers, which usually operate at about 90% efficiency.
When we install these systems, our customers often ask about noise. While older models could be a bit intrusive, today’s units are generally quiet enough not to disturb daily life – more like a fridge hum than anything disruptive. Routine maintenance is minimal, and many systems can be integrated with smart controls, making them easier to manage than people might expect.
Ground Source Heat Pumps: How They Work
Ground source heat pumps (GSHPs) function on the same principle – moving heat from one place to another – but instead of drawing it from the air, they use the natural warmth stored in the ground. Just a few metres below the surface, the ground maintains a relatively constant temperature all year round, usually between 10°C and 12°C in the UK. GSHPs use this stable heat source to provide consistent heating.
To collect that warmth, a ground loop of pipes is buried in the garden or land surrounding your home. These pipes are filled with a mixture of water and antifreeze that circulates and absorbs the heat. That low-grade heat is then compressed and transferred to the building’s heating system. There’s also the option of vertical boreholes for properties with limited space, though these require specialist drilling equipment and can be more expensive to install.
From our experience, ground source systems tend to have higher upfront costs compared to air source units, largely due to the digging and pipework involved. However, they tend to be slightly more efficient and can last longer with fewer moving parts exposed to the weather. For properties with adequate outdoor space and a long-term view on energy savings, a ground source heat pump can be a solid investment.
What Kind of Heating Experience Can You Expect?
One of the biggest differences between heat pumps and traditional gas boilers is how they deliver heat. Rather than producing sudden bursts of high-temperature warmth, heat pumps work best when providing steady, lower-temperature heat over a longer period. That means radiators might feel warm rather than hot, and your home will feel consistently comfortable rather than heating up and cooling down sharply throughout the day.
That steady temperature is something many people come to prefer – it feels gentler and more natural. With underfloor heating in particular, the experience is often described as more evenly distributed, without the chilly corners you sometimes get with radiators. It’s a slightly different way of living with heat, but one that fits well with the way we use homes today – especially those of us working from home or spending more time indoors.
Efficiency, Savings, and Incentives
Installing a heat pump does require an upfront investment, but the long-term savings can be significant – especially when paired with good insulation. Air source heat pumps usually cost less to install than ground source systems, but both may qualify for government incentives like the Boiler Upgrade Scheme, which offers grants of up to £7,500 in England and Wales for low-carbon heating systems. You can find more about this through GOV.UK’s guidance.
From an energy-saving perspective, we’ve seen real results with customers who’ve switched from old gas or oil boilers. Many experience lower running costs, especially if they’re using the heat pump with solar panels or a time-of-use tariff that rewards off-peak electricity use. As always, results vary based on how well the home is insulated, the size of the property, and the system design, which is why a proper survey and design process is so important.
Maintenance and Lifespan
Heat pumps require less day-to-day maintenance than many assume. Most systems will need an annual service to check refrigerant levels, electrical connections, and filters, but there’s no need for regular gas safety checks or flue inspections like you’d have with a boiler. With proper care, air source heat pumps can last around 15 years, while ground source systems often last 20–25 years or more.
We always encourage homeowners to think of heat pumps as part of a wider energy strategy – combining them with insulation, smart controls, and sometimes solar power. The experience isn’t just about heating; it’s about how your whole home uses and retains energy.
Heat pumps offer a reliable, efficient way to heat homes in the UK – and they’re becoming increasingly practical thanks to improvements in technology and support from government schemes. Whether you’re considering an air source or ground source system, understanding how they work can help you make an informed choice about your home’s future. Our experience with these systems has shown that with the right setup, they deliver comfort, reliability, and long-term value – without the carbon cost of traditional heating.
