Air Source Heat Pump Cost UK: Full 2026 Breakdown
If you are researching air source heat pumps, cost is probably your biggest concern. And with good reason — the figures quoted online range from wildly optimistic to absurdly expensive, making it nearly impossible to know what you should actually expect to pay.
This guide provides a detailed, honest breakdown of every cost involved in an air source heat pump installation in 2026. We have based these figures on current MCS installer data, manufacturer pricing, and real quotes from across the UK. No rounding down to make it look cheap. No inflating prices to scare you.
Just the real numbers.
Total Cost Summary
Here is the headline summary. We break each element down in detail below.
| Property Type | Typical System Size | Total Cost (Before Grant) | BUS Grant | You Pay |
|---|---|---|---|---|
| 1-2 bed flat or terrace | 5-6 kW | £8,000 – £11,000 | -£7,500 | £500 – £3,500 |
| 3-bed semi-detached | 8-10 kW | £10,000 – £14,000 | -£7,500 | £2,500 – £6,500 |
| 3-4 bed detached | 10-14 kW | £12,000 – £17,000 | -£7,500 | £4,500 – £9,500 |
| 5+ bed large detached | 14-16 kW | £15,000 – £22,000 | -£7,500 | £7,500 – £14,500 |
These ranges cover the majority of installations but do not include optional extras like underfloor heating, extensive radiator replacements, or major insulation work. Those are covered separately below.
Cost Breakdown by Component
The Heat Pump Unit
The outdoor unit itself — the actual heat pump — typically costs between £3,000 and £7,000 depending on the brand, capacity, and model. Here are approximate unit costs for popular brands at common sizes:
| Brand / Model | 8 kW | 12 kW | 16 kW |
|---|---|---|---|
| Daikin Altherma 3 | £3,500 – £4,200 | £4,500 – £5,500 | £5,500 – £6,500 |
| Vaillant Arotherm plus | £3,800 – £4,500 | £4,800 – £5,800 | £5,800 – £7,000 |
| Mitsubishi Ecodan | £3,200 – £4,000 | £4,200 – £5,200 | £5,200 – £6,200 |
| Samsung EHS Mono | £2,800 – £3,500 | £3,500 – £4,500 | £4,500 – £5,500 |
| Grant Aerona3 | £3,000 – £3,800 | £3,800 – £4,800 | £4,800 – £5,800 |
For detailed brand comparisons including efficiency and warranty, see our best air source heat pumps guide.
Hot Water Cylinder
You will need a hot water cylinder — heat pumps cannot work as combis. If you are replacing a system boiler and already have a cylinder, you may be able to keep it, but most installations include a new one designed for heat pump use.
- 170-litre cylinder: £600 – £900 (suitable for 1-2 people)
- 210-litre cylinder: £700 – £1,100 (suitable for 2-3 people)
- 250-litre cylinder: £900 – £1,300 (suitable for 3-4 people)
- 300-litre cylinder: £1,100 – £1,600 (suitable for 4+ people or high hot water demand)
Heat pump cylinders have a larger coil than standard cylinders to work efficiently at lower temperatures. A standard boiler cylinder may work but will likely reduce hot water performance.
Installation Labour
A typical installation takes 2-4 days with a team of 2-3 people. Labour costs vary significantly by region:
- London and South East: £2,500 – £4,000
- Midlands and South West: £2,000 – £3,500
- North of England: £1,800 – £3,000
- Scotland: £1,800 – £3,000
- Wales: £1,800 – £3,000
Pipework and Plumbing
Connecting the outdoor unit to the indoor system, plus any modifications to existing pipework. Costs depend on the distance between the outdoor unit and the cylinder, and on the complexity of the existing system.
- Simple installation (short pipe run, minimal changes): £500 – £1,000
- Average installation: £1,000 – £2,000
- Complex installation (long pipe run, major changes): £2,000 – £3,500
Electrical Work
The heat pump needs its own dedicated electrical supply, usually a 32A or 40A circuit from your consumer unit. An electrician will need to install this and may need to upgrade your consumer unit if it lacks capacity.
- New circuit only: £300 – £600
- New circuit plus consumer unit upgrade: £600 – £1,200
- Three-phase supply upgrade (rare, large systems only): £1,500 – £3,000+
Concrete Base and Groundworks
The outdoor unit sits on a concrete base or anti-vibration mounts. This is a minor cost for most installations:
- Pre-cast concrete pad: £100 – £200
- Poured concrete base: £200 – £400
- Wall-mounted bracket (alternative): £150 – £300
Controls and Commissioning
Your heat pump needs a controller (usually included with the unit), room thermostat(s), and potentially a hot water programmer. Commissioning — testing and optimising the system — is included in the installation but takes time to get right.
- Basic controls (included with most units): £0 – £200
- Smart thermostat addition: £150 – £350
- Multi-zone controls: £300 – £600
Additional Costs That May Apply
Not every installation needs these, but many do. Be prepared for them in your budget.
Radiator Upgrades
Because heat pumps run at lower flow temperatures than boilers, some or all of your radiators may need to be larger to deliver the same heat output. This is the most common "surprise" cost.
- No radiator changes needed: £0 (possible if you have modern, generously sized radiators)
- 3-5 radiators upgraded: £1,000 – £2,500
- Full house radiator replacement: £2,500 – £5,000
Read more about this in our guide on whether you need new radiators for a heat pump.
Underfloor Heating
If you are renovating or have the opportunity to install underfloor heating, it works brilliantly with heat pumps because of the low flow temperatures required. However, it is a significant additional cost:
- Ground floor only (retrofit): £3,000 – £6,000
- Ground floor only (new build/renovation): £2,000 – £4,000
Insulation Improvements
While not strictly part of the heat pump installation, improving insulation before fitting a heat pump can reduce the size (and cost) of system you need, and improve running costs significantly.
- Loft insulation top-up: £300 – £600
- Cavity wall insulation: £800 – £1,500
- Draught-proofing: £200 – £400
The Boiler Upgrade Scheme Grant
The BUS grant provides £7,500 towards the cost of an air source heat pump installation in England and Wales. This is the single biggest factor making heat pumps affordable for most households.
Key facts about the BUS grant:
- Applied as a discount at the point of installation — you do not pay the full price and claim back
- Your installer applies for it on your behalf
- Your property must have a valid EPC (Energy Performance Certificate)
- The installer must be MCS-certified
- The grant covers air-to-water heat pumps (not air-to-air)
- Available for existing homes, not new builds
For full eligibility details, application process, and regional alternatives, see our comprehensive air source heat pump grants guide or visit our grants page.
Cost Comparison: Heat Pump vs Gas Boiler
A new gas boiler installation costs £2,000-£4,500. An air source heat pump costs significantly more upfront, even after the grant. So is it worth the extra cost?
The answer depends on your situation. Here is a 15-year comparison for a 3-bed semi:
| Cost Element | Gas Boiler | Air Source Heat Pump |
|---|---|---|
| Installation cost | £3,500 | £12,000 |
| BUS grant | N/A | -£7,500 |
| Net installation cost | £3,500 | £4,500 |
| Annual fuel cost | £850 | £750 |
| Annual maintenance | £100 | £120 |
| 15-year total cost | £17,750 | £17,550 |
In this example, the total cost over 15 years is roughly equivalent. However, gas prices are widely expected to increase faster than electricity prices over the next decade, and the heat pump will outlast the boiler (20-25 years vs 12-15 years). For off-gas properties replacing oil or LPG, the economics strongly favour a heat pump.
For a comparison tailored to your property, visit our heat pump vs gas boiler page or try our cost calculator.
How to Reduce Your Costs
- Get at least three quotes: Prices vary enormously between installers. We have seen quotes differ by £4,000+ for the same property
- Ensure you qualify for the BUS grant: Get your EPC sorted before requesting quotes
- Consider a heat pump tariff: Several energy suppliers offer electricity tariffs specifically for heat pump owners, typically 17-20p/kWh versus 24-28p standard
- Improve insulation first: Better insulation means a smaller, cheaper heat pump and lower running costs
- Do not oversize the system: A properly sized heat pump is cheaper to buy and cheaper to run than an oversized one
Ready to get real quotes for your property? Use our free quote service to be matched with MCS-certified installers in your area.
Frequently Asked Questions
Why do heat pump quotes vary so much?
Installation complexity varies hugely between properties. A straightforward replacement in a well-insulated home with suitable radiators costs far less than one requiring extensive pipework changes, radiator upgrades, and a new electrical supply. Installer margins also vary — some companies charge significantly more for the same equipment and work.
Is it cheaper to install a heat pump during a renovation?
Yes, often significantly so. If you are already replacing your heating system, upgrading radiators, or installing underfloor heating, the marginal cost of going with a heat pump rather than a boiler is much lower. New builds and deep renovations are the most cost-effective scenario for heat pumps.
Can I finance a heat pump installation?
Many installers offer finance options, typically 0% interest for 12-24 months or low-interest plans over 5-10 years. Some local authorities also offer green home improvement loans at preferential rates. In Scotland, Home Energy Scotland provides interest-free loans.
Do I need to pay for the heat pump upfront?
No. The BUS grant is applied directly as a discount on your invoice, so you only pay the net amount. Most installers will require a deposit (typically 10-25%) when you accept the quote, with the balance due on completion.
Will the cost of heat pumps come down?
Prices have been falling steadily as production volumes increase and competition grows. Industry forecasts suggest costs will continue to decrease by 3-5% per year over the next few years. However, waiting too long risks missing the current grant, which may not be renewed at the same level.
Next Steps
Understanding costs is important, but the best way to get an accurate figure for your home is to get real quotes. Here is what we recommend:
- Use our heat pump calculator for an initial estimate
- Read our installation guide so you know what to expect
- Get free quotes from MCS-certified installers in your area
Return to our complete guide to air source heat pumps for the full overview.