There is still a lot of confusion around heat pumps, especially online. You will see people saying they are brilliant, people saying they are useless, and plenty in between. In my experience, the truth is much simpler: a properly designed and properly installed heat pump can work very well in UK winter conditions.

The problems usually come when systems are badly designed, badly set up or sold to homeowners without properly explaining how they work. That is where people end up disappointed, and that is often what feeds the myths.

So, do heat pumps actually work when it is cold outside?

Yes. Modern air source heat pumps are designed to keep working in cold temperatures, including the sort of winter weather we typically get in the UK. They do not suddenly stop working just because it is cold.

In fact, they are specifically made to extract heat from the outside air even when the air feels cold to us. That is the bit that often sounds strange at first, but it is how the technology works. There is still heat energy in the air, and the heat pump uses that energy and transfers it into the home.

The UK climate is actually quite well suited to heat pumps overall. We are not dealing with months and months of extreme sub-zero temperatures in the same way some much colder countries do, and plenty of heat pumps operate successfully in places that get colder than we do.

Why do some people think heat pumps do not work in winter?

Usually because they have either heard second-hand stories or come across systems that were not right in the first place. A heat pump is not a magic box that can ignore poor design. Like any heating system, it has to be suited to the property and commissioned properly.

The most common reasons people have a poor experience tend to be things like:

• the unit being the wrong size for the property
• radiators not being suitable for the way the system needs to run
• poor heat loss calculations or weak design work
• controls not being set up properly
• the homeowner expecting it to behave exactly like a gas boiler

That last one is a big one. A boiler often heats in shorter, hotter bursts. A heat pump generally works best by running more steadily and more efficiently. It is a different style of heating, and once people understand that, it usually makes much more sense.

Do they still heat the house properly?

Yes, they can heat a house properly, and when they are done right they often provide a very comfortable type of heat. Instead of the home swinging between too hot and then cooling off again, a good heat pump system can give a more stable, even warmth.

A lot of homeowners are surprised by that. They expect a lower-temperature system to feel weaker, but in reality comfort is not just about how hot the radiators feel. It is about whether the home stays consistently warm.

In many cases, that steady background heat can feel better to live with than short bursts of very high heat.

What makes the biggest difference to winter performance?

If I had to narrow it down, I would say the biggest factors are design, radiator suitability, heat loss and commissioning.

1. Proper heat loss calculations

This is the starting point. If the property is not assessed properly, everything that follows is built on shaky ground. A good design should be based on what the house actually needs, not guesswork.

2. Suitable emitters

Because heat pumps usually run at lower temperatures than boilers, the emitters matter. Sometimes the existing radiators are fine. Sometimes some need upgrading. It depends on the property and the design.

3. Correct system setup

Even a good installation can underperform if it is not set up properly. Flow temperatures, controls and commissioning all matter. That is why optimisation is such an important part of the process.

4. Realistic expectations

A heat pump is not there to behave exactly like an old boiler. It is there to heat the house efficiently and steadily. Once that is understood, people usually find the system makes a lot more sense.

Are they only suitable for new-build houses?

No, and this is one of the biggest myths still floating around. Heat pumps are not only for brand new homes. Plenty of existing properties can be suitable, including older homes, but the property still needs to be looked at properly.

Some houses are straightforward. Others need a bit more thought. In some cases, insulation improvements or radiator upgrades may help the system perform better, but that does not mean older homes are automatically ruled out.

Across Northamptonshire, Bedfordshire and surrounding areas, a lot of homes are existing properties rather than idealised new-builds, so this is a real-world consideration, not a theoretical one.

What about frost and defrost cycles?

This is another thing that worries people, but it is a normal part of how heat pumps operate in colder weather. When conditions are right, frost can build up on the outdoor unit, and the system will occasionally go through a defrost cycle to clear it.

That is normal. It does not mean the system is failing. A properly functioning heat pump is built to deal with that. Homeowners sometimes notice it and assume something is wrong, when really it is just part of normal cold-weather operation.

Will a heat pump leave me cold on the coldest days?

It should not, assuming the system is right for the house and has been designed correctly. That is really the key point. The coldest days are exactly why proper design matters. You do not size and set up a system based only on mild weather.

In my opinion, the best way to avoid problems is to get the design right from the start and make sure the customer understands how the system is meant to run. That removes a lot of the issues before they even start.

Why do some customers end up loving their heat pump?

Usually because it has been matched to the property properly, set up properly and explained properly. When that happens, many homeowners find they like the more stable comfort, the efficiency and the lower-carbon side of it as well.

A lot of the success comes down to treating the whole heating system as a system, not just swapping one box for another and hoping for the best.

• steady and comfortable warmth
• good efficiency when designed correctly
• works well in typical UK winter conditions
• lower-carbon option compared with gas or oil systems
• strong long-term heating solution for many homes

Final thoughts

So, do heat pumps work in UK winters? Yes, they do. But the better answer is this: heat pumps work well in UK winters when the system is designed, installed and set up properly.

That is really the point people need to understand. The issue is not usually the weather itself. More often, it is poor design, poor setup or poor advice that causes problems.

If the property is assessed properly and the system is right for the home, a heat pump can be a very effective and comfortable way to heat a house right through winter.