Are heat pumps worth it in the UK?
A heat pump replaces your gas boiler with a unit that runs on electricity and moves heat rather than burning fuel. The headline worry is always the same: it costs more to fit, so does it actually save money? The honest answer is that the upfront cost has dropped sharply thanks to a £7,500 government grant, while running costs land anywhere from a little cheaper to a little dearer than gas depending on your home, your installer and your tariff. This guide puts real UK numbers on both sides so you can see where a heat pump pays and where it doesn't.
How a heat pump works, in plain terms
A fridge moves heat out of the cabinet and dumps it into your kitchen. An air source heat pump does the same trick in reverse: it pulls warmth out of the outside air, even in winter, and concentrates it to heat your water and radiators. Because it's moving existing heat rather than creating it, it delivers more energy than it uses. That ratio is the whole game.
The measure is the SCOP, the seasonal coefficient of performance. A SCOP of 3.5 means that for every unit of electricity the pump draws, it delivers about 3.5 units of heat. A gas boiler, by contrast, is around 90% efficient: a unit of gas gives you 0.9 units of heat. That efficiency gap is what lets a heat pump compete even though electricity costs more per unit than gas.
What it costs to install
An air source heat pump system typically costs £8,000 to £14,000 fitted, including the unit, a hot water cylinder, and any radiator or pipework changes. The big offset is the Boiler Upgrade Scheme, which gives households in England and Wales a £7,500 grant towards an air or ground source heat pump. Your MCS-certified installer applies for it and takes it straight off the bill, so you don't pay it out and claim it back. The mechanics, eligibility and how to apply are covered in the Boiler Upgrade Scheme explained.
| Item | Typical figure |
|---|---|
| Air source heat pump, installed | £8,000 to £14,000 |
| Boiler Upgrade Scheme grant (England & Wales) | minus £7,500 |
| Typical net cost to you | £500 to £6,500 |
| For comparison: new gas boiler | £2,500 to £4,500 |
After the grant, a heat pump often lands within a few thousand pounds of a new boiler, which is a very different picture from a few years ago. Scotland runs a separate scheme through Home Energy Scotland, with a grant of up to £7,500 plus an optional interest-free loan.
Running costs: the honest comparison
This is where it gets specific. Gas runs at roughly 6 to 7p per kWh; standard electricity is around 24 to 25p. On those figures, electricity is about 3.5 to 4 times the price of gas per unit. So a heat pump only breaks even on running cost if its SCOP roughly matches that ratio.
Here's a worked year for a typical home needing 12,000 kWh of heat:
| System | How the sum works | Annual running cost |
|---|---|---|
| Gas boiler (90%) | 12,000 ÷ 0.9 = 13,333 kWh gas at 6.5p | ~£867 |
| Heat pump (SCOP 3.5), standard tariff | 12,000 ÷ 3.5 = 3,429 kWh at 25p | ~£857 |
| Heat pump (SCOP 3.5), heat-pump tariff | 3,429 kWh at ~15p blended | ~£514 |
On a standard tariff the two are roughly level. The real saving appears on a specialist heat-pump tariff such as those from Octopus and others, which offer a cheaper unit rate for heat-pump households. Pair a good SCOP with the right tariff and a heat pump runs meaningfully cheaper than gas. Fit it badly, on a high flow temperature with no tariff change, and it can cost more. The installer matters as much as the kit.
Which homes a heat pump suits
Heat pumps deliver heat at a lower temperature than a gas boiler, around 35 to 50C rather than 60 to 70C. That means the heat has to come from larger radiators or underfloor heating, and the home has to hold onto it. The better insulated your house, the better a heat pump performs.
- Strong fit: a reasonably insulated home with loft and cavity wall insulation, and space outside for the unit.
- Workable with upgrades: older homes, once a few radiators are sized up and draughts are dealt with.
- Harder: solid-wall properties with no insulation, where you'd want to improve the fabric first.
A good installer will do a room-by-room heat-loss survey rather than just swapping like for like. That survey is the single most useful thing an industry professional brings, and it's worth insisting on.
Do heat pumps work in cold weather?
Yes. They're the standard form of home heating across Scandinavia, where winters are far harder than ours. Output and efficiency drop on the coldest days, which is why correct sizing matters, but a properly specified unit keeps a UK home warm through a normal winter. The "they don't work when it's cold" line is the heat-pump equivalent of the solar myths covered in solar panel myths.
So, are they worth it?
For a reasonably insulated home, with the grant, a competent install and a heat-pump tariff: increasingly, yes, on both running cost and carbon. For a poorly insulated solid-wall home with no tariff change, the case is weaker until you improve the fabric first. The technology is sound; the result depends on getting the details right. As with solar, the smart move is to model your own home rather than trust an average.
Frequently asked questions
They can be. On a standard electricity tariff a well-installed heat pump is roughly level with gas; on a specialist heat-pump tariff it's usually cheaper. A poor install on a high flow temperature can cost more.
Around £8,000 to £14,000 installed, less the £7,500 Boiler Upgrade Scheme grant in England and Wales, so often £500 to £6,500 net.
Yes. Efficiency dips on the coldest days, but a correctly sized unit heats a UK home through winter. They're standard across colder countries than ours.
Sometimes. Heat pumps run cooler, so some radiators may need sizing up or underfloor heating in places. A heat-loss survey tells you which.
Partly. Solar offsets some of the electricity, mostly in the warmer months when heating demand is low, so the overlap is modest but real. The combined picture is in solar, heat pumps and EVs.