Heating your home in the UK is getting more expensive by the year. Gas bills in the UK keep rising, and traditional heating systems like gas boilers aren’t just costly—they’re also bad for the environment.
If you’re worried about staying warm without breaking the bank—or harming the planet—air source heat pumps (ASHPs) offer a compelling solution. But a common question many homeowners ask is: “Do heat pumps actually work in cold UK winters?”
The answer is a confident yes. Modern ASHPs are designed to deliver reliable heating even when temperatures drop below freezing, making them suitable for most UK homes.
In this guide, we’ll explain what makes them suitable for UK winters, how they perform in sub-zero temperatures, and why they’re becoming the go-to choice for homeowners across the country.
Modern ASHPs are designed to perform in cold climates. Research and real-world trials show that:
UK government trials, including the Electrification of Heat Demonstration Project, found that ASHPs maintained high efficiency during the coldest days. In fact, homeowners reported satisfaction rates above 80%, with most enjoying lower running costs compared to gas or oil.
Large-scale UK field trials from the Energy Saving Trust found ASHPs consistently achieved COPs above 2 across British winters. Careful design, installation quality, and home insulation levels remain important, but do not prevent good cold performance.
In Nordic countries such as Finland, Sweden, and Norway, winters are much colder than in the UK. Yet millions of homes use air source heat pumps, showing they work even in harsh winters.
| Outside Temperature | Typical ASHP Efficiency (COP) | How it Compares to a Gas/Oil Boiler |
|---|---|---|
| +7°C | 3.7 | ~4× more efficient |
| 0°C | 3.0 | 3× more efficient |
| -7°C | 2.0–2.5 | 2–2.5× more efficient |
| -15°C | 1.8–2.2 | 1.8–2× more efficient |
| -20°C | 1.5–2.0 | 1.5–2× more efficient |
| -25°C (cold-climate units) | 1.3–1.5 | Still above 1.5× efficient |
For most UK homes, a backup system isn’t necessary. Modern air source heat pumps deliver steady, reliable heat even when the temperature drops below freezing. That makes them a great fit for most UK homes. Even when the temperature drops well below freezing, these systems maintain efficiency and comfort.
In homes that are poorly insulated or extremely large, some people choose a hybrid setup (heat pump plus a boiler) for extra flexibility—but it’s not required for the vast majority of households.
Thanks to technological innovations, ASHPs remain efficient even in freezing weather. Key features include:
These innovations mean most UK homes don’t need a backup heating system, even during the chilliest winter days.
Insulation: Improve loft, walls, and draught-proofing to maximise efficiency.
Radiators: Low-temperature or larger radiators help maintain comfortable indoor temperatures.
Hybrid Options: Rarely needed in the UK, but can be considered in older, poorly insulated homes.
Smart Controls: Weather-compensated or programmable systems help optimise energy use.
In short, air source heat pumps are a reliable, efficient, and environmentally friendly option for UK homes, even in cold weather.