HEAT PUMPS GUIDE
Types of Heat Pump: Air-Source, Ground-Source, Hybrid & Air-to-Air Compared 2026
A heat pump system heats your home by pulling warmth from outside air or ground, even in winter.
A heat pump system heats your home by pulling warmth from outside air or ground, even in winter.
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A heat pump system heats your home by pulling warmth from outside air or ground, even in winter. Costs range from £7,000 to £14,000 for air source and £15,000 to £35,000 for ground source, but the Boiler Upgrade Scheme knocks £7,500 off either type. Most UK homes can have one fitted, though you'll need decent insulation first. Here's what you actually need to know before committing.
Forget the complicated diagrams for a moment. A heat pump works like a fridge in reverse.
Your fridge pulls heat out of its interior and dumps it into your kitchen. A heat pump does the opposite: it grabs heat from outside, whether that's the air, the ground, or a nearby water source, compresses it to a higher temperature, and pushes it into your radiators or underfloor heating. The key thing that surprises most people is that this works perfectly well when it's 0°C or even minus 5°C outside. There's still thermal energy in cold air, and modern heat pumps are designed to extract it efficiently down to around minus 15°C to minus 20°C.
Three main types exist:
How efficient are they? That's measured as a Coefficient of Performance, or COP. A COP of 3 means for every 1kW of electricity the pump uses, it produces 3kW of heat, roughly three times more efficient than a gas boiler, which can never exceed 1:1. In practice, seasonal averages (called SCOP) tend to sit between 2.5 and 3.5 for air source and 3.5 to 4.5 for ground source, according to the Energy Saving Trust.
So yes, you're running on electricity. But you're using far less of it than you'd expect.
£10,000 to £13,000. That's the realistic range for a typical air source heat pump installation in a 3-bed semi after the Boiler Upgrade Scheme grant is applied.
Here's how the numbers break down before grants:
| System type | Typical cost (installed) | After BUS grant |
|---|---|---|
| Air source heat pump | £7,000–£14,000 | £0–£6,500 |
| Ground source heat pump | £15,000–£35,000 | £7,500–£27,500 |
Why such wide ranges?
Because every installation is different. A simple swap in a well-insulated new-build with underfloor heating already in place might come in at the lower end. A Victorian terrace that needs new radiators, a hot water cylinder, and electrical upgrades will be at the top. The spread between those two scenarios can be £8,000 or more, which is why anyone quoting you a fixed price without visiting the property first is guessing.
Here's the honest bit. The heat pump unit itself is only about 40% to 50% of the total cost. The rest goes on installation labour, a new hot water cylinder (most systems need one), possible radiator upgrades, pipework modifications, and the MCS certification paperwork.
When someone quotes you £7,000, ask whether that includes everything or just the box on the wall.
Running costs are where heat pumps start to look genuinely attractive. At current electricity rates of roughly 24.5p per kWh and gas at around 6.8p per kWh, a heat pump with a SCOP of 3 gives you an effective heating cost of about 8.2p per kWh, competitive with gas. But on a smart electricity tariff like Octopus Agile or Intelligent Octopus Go, where off-peak rates drop to 7p to 10p, the maths tip firmly in the heat pump's favour.
We've seen cases where homeowners on time-of-use tariffs are heating their homes for less than they spent on gas. Not common yet. But it's happening.
Two schemes are currently open that can cut the cost of a heat pump system, and one of them is genuinely generous.
The Boiler Upgrade Scheme is the big one. £7,500 off an air source or ground source heat pump. £5,000 off a biomass boiler. You don't need to be on benefits. You don't need a low income. You just need to own the property, have a valid EPC, and use an MCS-certified installer. The installer applies on your behalf and the grant comes off your invoice directly, you never handle the money. The scheme runs until 2030 under the Warm Homes Plan, according to GOV.UK.
That's it. No means test.
For lower-income households, ECO4 can potentially fund the full cost of a heat pump if you receive qualifying benefits like Universal Credit, Pension Credit, or Child Tax Credit. ECO4 runs until December 2026, and eligibility depends on both your benefits status and your home's current EPC rating. If you think you might qualify, check our free boiler scheme guide which covers ECO4 eligibility in detail.
What about local funding? The Warm Homes: Local Grant is administered by local authorities, so what you get depends entirely on where you live. Some councils are funding heat pumps directly, others are focusing on insulation. Amounts vary. The scheme runs until 31 March 2028 and we've written a full breakdown of how it works.
One thing worth noting: the Great British Insulation Scheme closed in March 2026. It's gone. But ECO4 and BUS between them cover most of what GBIS used to offer.
Almost certainly. With caveats.
The biggest factor isn't your home's age or type. It's insulation. A heat pump operates at lower flow temperatures than a gas boiler, typically 35°C to 45°C compared to 60°C to 80°C, which means your home needs to hold onto heat more effectively. If warmth is leaking through thin walls, single-glazed windows, or a poorly insulated loft, the heat pump has to work harder, your bills go up, and the whole system underperforms.
So before you think about a heat pump, think about insulation. Loft insulation is the cheapest win. Wall insulation makes the biggest difference. Better windows help too, though the payback period is longer.
Right, the practical stuff.
You'll need outdoor space for the unit. For an air source system, that's roughly 1m x 1m of clear wall space with good airflow around it. Doesn't need planning permission in most cases (permitted development covers most domestic ASHPs), but there are rules about distance from boundaries and noise levels.
Ground source needs more space: either a large garden for horizontal loops or access for a borehole.
Radiators can be a sticking point. Because heat pumps run at lower temperatures, your existing radiators might need to be larger to deliver the same warmth. Some homes need a full radiator swap. Others just need one or two upgraded in the rooms that struggle. A good installer will do a room-by-room heat loss calculation before quoting, and honestly, if they don't offer to do this unprompted, find a different installer.
And you'll need an EPC. Not just for the grant application, but because a decent installer will want to see it to design your system properly. If you don't have one, they cost £35 to £120.
Who should think twice? If you've got a well-insulated home, a gas boiler that's less than five years old, and no strong environmental motivation, the financial case for switching right now is thin. The running cost savings exist but they're modest compared to a modern gas system, and the upfront cost even after the grant is significant. We think the calculus changes within two to three years as gas prices rise and electricity tariffs get smarter, but we'd rather be honest about where things stand today.
There's no single best heat pump. There's only the best one for your house, your budget, and your heating pattern.
For most UK homes, an air source heat pump is the right call. They're cheaper to install, they work on terraces and semis with small gardens, and the technology has matured significantly. Brands like Vaillant, Daikin, and Samsung are all producing reliable units with 10-year warranties. We've reviewed the top brands in detail if you want to compare specifics.
Ground source? Narrower set of situations. If you've got a large garden, you're building from scratch, or you're in a rural property off the gas grid, the higher upfront cost pays back over time through better efficiency. A ground source system in the right property can hit a SCOP of 4 or above, which means your heating costs could be 30% to 40% lower than with air source.
Air-to-air is the budget option, but we wouldn't recommend it as your primary heating system unless you're supplementing something else. No hot water. No radiator integration. Better suited as a top-up in a well-insulated flat or a single room that's hard to heat.
Two things to insist on when choosing an installer:
The installer matters more than the brand. A well-installed mid-range unit will outperform a premium unit that's been badly sized or poorly commissioned every single time. Get three quotes minimum.
2 to 4 days. That's a typical air source heat pump installation. Ground source takes longer, sometimes a week or more if trenching is involved.
Day one is usually the outdoor unit, pipework, and any electrical work. Day two covers the indoor components: the hot water cylinder, controls, and connecting everything to your existing heating circuit. If you need new radiators, add another day. The MCS certification and commissioning happen at the end, and your installer should walk you through the controls and settings before they leave.
It's not silent.
That's worth being upfront about. An air source heat pump produces a low hum, typically 40 to 45 decibels at one metre, about the level of a quiet conversation. You'll hear it if you're standing next to it. You won't hear it from inside the house with the windows shut. Neighbours might notice it in very quiet rural settings, which is why there are planning rules about placement near boundaries.
After installation, expect a learning curve. Heat pumps work best when you set them to a steady temperature and leave them running, rather than the blast-it-for-an-hour approach most of us use with gas boilers. The thermostat becomes your best friend. Smart controls from brands like Hive or tado° can optimise when the system ramps up and down based on weather forecasts and your schedule.
Annual servicing? About £100 to £200. Less than a gas boiler service, and there's no gas safety certificate to worry about.
One thing that catches people off guard: your electricity bill will go up. Obviously, you're running your heating on electricity now. But your gas bill disappears entirely, and the net effect for most homes is a saving. How much depends on your insulation, your tariff, and how warm you like your house.
Based on Energy Saving Trust data, a typical home switching from gas should expect annual heating costs of £500 to £900 on a heat pump, compared to £700 to £1,000 on gas. Smart tariffs can push heat pump costs lower still.
The system should last 20 to 25 years with proper maintenance, significantly longer than a gas boiler's typical 12 to 15 year lifespan. So while the upfront cost is higher, you're spreading it over a much longer period.
Open our eligibility checker. Two minutes. You'll see exactly which grants apply to your home and how much you could save on a heat pump system.
Common questions