climate change sustainability technology

Seven heat pump myths

Heat pumps are an important technology in reducing carbon from Britain’s heating. As a country we have made good progress on reducing emissions from electricity. Heating is a bigger challenge. 85% of homes have gas boilers, and gas is of course a fossil fuel. We need to reduce and eventually eliminate gas boilers.

In typical British fashion, this whole process has become a bete noire for the tabloids. Like electric cars, smart meters and wind turbines, editors have taken a hysterical aversion to heat pumps. Take this article from The Express, which claimed to have had a conversion to green issues just two years ago:

  • Gas boiler ban fury: ‘Madcap scheme’ forces firms to sell heat pumps Brits can’t afford

    The latest attack on the nation’s 26 million gas boilers will see the Government slap £5,000 fines on companies unless they sell costly heat pumps to people who don’t want and can’t afford them.

Look at the language here: anger, fury, madness. Force, attack. It’s the language of violence. You’d think the campaign for renewable heat was being driven by Vladimir Putin. This is par for the course for The Express, but the article is just an extreme example of some very common views that I see and hear regularly. Putting aside some complexities about types of heat pumps for now, let’s look at some of those views and whether there’s anything to them.

Heat pumps are a new and unproven technology
This is a common one – it’s too early to tell if they work. Not sure where this came from, other than being endlessly repeated until it becomes conventional wisdom. There’s no basis for it: the underlying science was described by Lord Kelvin in 1852 and the first working heat pump was built in Austria that same decade. It wasn’t until the 1940s that anyone installed a heat pump at scale, and a council building in Norwich was the first. Unfortunately it was never prioritised as a technology in the UK because fossil fuels were cheap. We never bothered with them, and so all the commercial development of this mostly British invention happened elsewhere. Sweden and Finland use them to make the most of their nuclear power. So does France, which has 4.25 million heat pumps installed. Japan went big on reversible heat pumps in the 1990s, providing heat or cool depending on the season. So it’s not true that they’re new and unproven – they’re just unfamiliar in the UK.

Heat pumps are too expensive
This has been true in the past, but it is changing fast and might not be true any more. The Express claims that the average cost of a new gas boiler is £2,000 while a heat pump is £13,000. They’ve exaggerated the comparison here by taking the lower end of estimates for gas and the highest possible for a heat pump. They’ve also neglected to mention that households don’t pay the whole cost of a heat pump: the government currently has a grant of £5-6,000 for new heat pumps as part of the Boiler Upgrade Scheme. The main problem has been economy of scale, and that has changed dramatically in recent years as larger companies have trained up staff to install heat pumps in larger numbers. British Gas and Octopus both start their heat pump offers at £3,000 – making it entirely competitive with a new gas boiler.

They are more expensive to run
Okay, heat pumps might be getting cheaper to install, but what about running it? Gas is indeed cheaper than electricity, but it doesn’t follow that heat pumps mean higher bills. That’s because heat pumps aren’t using electricity for heat. They use electricity to run the pump, and draw ambient heat from the environment. By using this free low-level warmth from the air, they generate three units of heat for every unit of electricity they consume. So if you currently use the average of around 12,000 kilowatts of gas energy every year to heat your home, you’d need 4,000kw of electricity to deliver the same heating with a heat pump. So you may already save money with a heat pump, and this will improve. If you have solar panels, even better. There are other factors in play, including insulation and radiator types, so it isn’t possible to say that heat pumps are definitively cheaper or definitively more expensive for everyone. It depends.

They don’t work in the cold
You do get a different kind of heating from a heat pump, and this may be where the misunderstanding has crept in. Heat pumps deliver a more constant lower level heat, rather than gas boilers that heat radiators to a higher temperature for a shorter time. For evidence that heat pumps work fine in the cold, consider the aforementioned Sweden and Finland. Both have notably colder and longer winters than the UK and yet heat pumps are the technology of choice for electrifying their heating. There are 1.5 million heat pumps in Finland, a country of 2.7 million households. The country with the fastest growth in heat pump use at the moment is Poland – also colder than the UK – where there was a 102% increase in sales in 2022.

They don’t work in old houses
Let’s be more specific: heat pumps aren’t a good solution for inefficient and leaky houses, and that’s not the same thing. Because heat pumps work at that lower level of heat, they don’t perform well in poorly insulated homes where heat is constantly escaping. A raging gas boiler will do a better job of keeping ahead of the wasted heat, but I’d hardly call that a working solution either, to be honest. The answer is to insulate a home properly first, something we should be doing regardless. My own house is from the 1920s – young by some standards, but still pre-central heating and pre-indoor plumbing. I’ve had a heating engineer look at it and they say a heat pump would work fine.

They’re so noisy!
“Whole streets could be plagued with noisy fans going 24/7” grumbles an Express reader in the comments section of the above article. I wonder if this person has ever seen or heard a heat pump, but it’s certainly a common complaint. Yes, air source heat pumps make a noise. It’s variable, so it will be quieter on warmer days and louder when it has to work harder. There’s a legal standard maximum for the noise they can make, and it’s a similar volume to a desk fan or the hum of a microwave. Hardly enough to ruin the neighbours’ barbecue, especially since the heat pump will make the most noise on days when it’s sub-zero temperatures and nobody’s hanging out on their patio. Older models were louder, so the noise rumours are perhaps a hangover from previous eras. Otherwise if a heat pump is making a racket, it’s probably broken.

They are being forced on people
There’s a perception that ‘the government is coming for your boiler’ that I’ve encountered on social media, and that’s pure paranoia. There are currently incentives and subsidies to make it cheaper for people who want one. That’s hardly forcing anyone’s hand. Government policy is uncertain under the Conservatives, but there are plans to stop fitting gas boilers in new homes from 2025. (Already pretty late, considering that it’s easier to fit a heat pump into a new build home that’s designed for it than to retrofit one later.) You’ll still be able to get a gas boiler if you want one. All gas boiler installations are due to end in 2035, so you’ve got many more years of burning fossils in your house if you’re too scared to try anything better. Even then, ‘the government’ won’t be coming round to rip out anyone’s boiler. You’ll be able to keep using it until it needs replacing, and then you’ll need to choose a low carbon form of heating. It may be a heat pump. It may not – other options are available, including a straight-up electric boiler or infra-red heating.

That’s not an exhaustive list of objections, just some of the more common myths on the internet. Yes, there are exceptions. I don’t want to argue with anyone’s favourite anecdote about their cousin’s colleague’s ex-wife’s friend whose neighbour got a heat pump and ruined everyone’s life while freezing to death surrounded by unpayable bills.

Not everyone will have a heat pump, and different sorts of building and homes will have different solutions or combinations of technologies. If you don’t want one, that’s fine – but the hatred of heat pumps is a strange phenomenon.


  1. Well said. Our house was built in 1901 with solid brick walls, rising damp and big sash windows. I hope to get the house ready to effectively use a heat pump, but the work required has been and will continue to be extensive. Draught proofing, triple glazed windows, interior wall insulation with damp proofing and so on. One advantage though is that the radiators already fitted should be suitable for the lower level of heat from a heat pump, since they were specified when the house was poorly insulated and draughty.
    However, a couple of our neighbours have been sold heat pumps when their houses were not suitably insulated and draught-proofed. It seems that the salespeople did not take this into consideration and they now complain of being cold despite large electricity bills. I fear that many heat pump installers are the new ‘double glazing salespeople’ – selling us an expensive product when all that was really needed was to get the windows properly air-tight with properly controlled ventilation and the use of thick curtains. Admittedly it is not easy to get an old sash window fully air-tight and insulated – I know because nearly all our windows are the original 1901 windows renovated. But when money is tight, it is in my view better spent on draught-proofing and insulation – not at first on new windows.
    So I fear that because some people – including I fear some with the ear of the government – can make a lot of money selling heat pumps as some sort of magical solution, people in older houses (and even quite new ones since our building standards are so poor) will be let down and this will feed the frenzy against heat pumps that you rightly criticize.
    Just how can we get draught proofing and insulation with controlled ventilation at the top of the agenda for our millions of badly built and poorly maintained houses?

    1. Yes, a similar thing happened when the Feed-In Tarriff was generously set and all kinds of cowboys started doing solar installations. A big part of the problem is the way that the government has repeatedly bungled energy efficiency. We need that alongside support for heat pumps.

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