This guide separates heat-pump equipment, installation, grants and running costs. Use complete quotes for the purchase decision and the worked energy example below to understand the assumptions behind a running-cost estimate.
An air source heat pump costs £7,000–£13,500 installed in the UK, with most air-to-water systems – the standard choice for radiator-based homes – priced at £8,000–£16,500 fully installed. The UK government’s Boiler Upgrade Scheme (BUS) provides a £7,500 grant, reducing the net cost to a typical £4,500–£6,000 for eligible properties. Labour accounts for £3,500–£6,000 of the total; the remainder is hardware.
The running-cost example below uses a stated annual heat demand and seasonal efficiency. Ask your installer for a property-specific estimate, including hot water and any radiator or insulation work.
Choose an MCS-certified installer and confirm that the proposed system is eligible for the grant. Air-to-air systems heat air directly, while air-to-water systems serve a water-based heating circuit. Their installation scope and hot-water arrangements differ.
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- A £12,000 quote less a £7,500 grant leaves £4,500 to pay - check eligibility and include all cylinder, radiator, electrical and commissioning work in the quote.
- Our space-heating example costs £979 a year on the standard tariff - it assumes 12,000kWh of useful heat and seasonal efficiency of 3.2, excluding hot water and fixed charges.
- Cheap tariff windows do not apply to all your electricity - use the average rate across heat-pump consumption and include expensive periods in the comparison.
- Payback depends on the alternative you would actually buy - compare the extra upfront cost with annual savings, and do not assume future fuel prices.
How Much Does an Air Source Heat Pump Cost?
An air source heat pump costs £7,000-£13,500 installed in the UK, with an average of £12,000 for an air-to-water system before the £7,500 BUS grant.
The total cost of an air source heat pump depends on the type of system, your property size, and the complexity of the installation. An air-to-water ASHP (the most common type, which connects to radiators and underfloor heating) costs more than an air-to-air unit (which blows warm air directly into rooms).
| Cost Component | Air-to-Water | Air-to-Air |
|---|---|---|
| Supply only | £3,850 – £13,300 | £2,000 – £5,000 |
| Installation labour | £3,500 – £6,000 | £2,000 – £4,500 |
| Total installed | £8,000 – £16,500 | £4,000 – £9,500 |
| BUS grant | £7,500 | £2,500 |
| Net cost after grant | £500 – £9,000 | £1,500 – £7,000 |
These figures include VAT, which is currently 0% on heat pump installations (until March 2027). After this date, the reduced 5% rate returns, adding roughly £450-£800 to the installed price.
Installation takes 2-5 days for a typical home. Factors that push costs higher include: difficult access for the outdoor unit, upgrading radiators to work at lower flow temperatures, adding a hot water cylinder, or upgrading the electrical supply.
Air Source Heat Pump Costs by Property Size
A 1-2 bed home needs a 5-7 kW heat pump costing £7,000-£9,000 installed, while a 4-bed detached house requires 10-16 kW at £11,000-£16,500.
Heat pump sizing is based on your home’s heat loss, which correlates roughly with property size. An undersized unit won’t heat your home adequately; an oversized one wastes money upfront and cycles inefficiently. Our heat pump sizing guide walks through the full calculation. A qualified MCS installer will perform a heat loss calculation before recommending a system.
| Property Type | System Size | Installed Cost | After BUS Grant |
|---|---|---|---|
| 1-2 bed flat or terrace | 5-7 kW | £7,000 – £9,000 | £0 – £1,500 |
| 3-bed semi-detached | 7-9 kW | £9,000 – £12,000 | £1,500 – £4,500 |
| 4-bed detached | 10-16 kW | £11,000 – £16,500 | £3,500 – £9,000 |
These costs assume an air-to-water system with no major additional works. Add £500-£1,500 for a new hot water cylinder if you’re replacing a combi boiler (which doesn’t use one), and up to £9,000 if all radiators need upgrading, though our guide to heat pump radiators explains why most homes only need a subset changed.
Air-to-Water vs Air-to-Air Heat Pumps
Air-to-water heat pumps cost £8,000-£16,500 and provide heating plus hot water. Air-to-air units cost £4,000-£9,500 but only provide space heating, not hot water.
Most UK installations are air-to-water systems because they replace a gas boiler like-for-like: they connect to your existing radiators (or underfloor heating) and provide domestic hot water via a cylinder. Air-to-air systems are simpler and cheaper but only blow warm air into rooms – you still need a separate system for hot water.
| Feature | Air-to-Water | Air-to-Air |
|---|---|---|
| Installed cost | £8,000 – £16,500 | £4,000 – £9,500 |
| Hot water | Yes (via cylinder) | No |
| Works with radiators | Yes | No |
| Works with UFH | Yes (ideal pairing) | No |
| Cooling in summer | Some models | Yes (reversible) |
| BUS grant | £7,500 | £2,500 |
| Best for | Whole-house heating replacement | Single rooms, extensions, offices |
Air-to-water is the right choice for most homeowners replacing a gas or oil boiler. Air-to-air makes sense for supplementary heating in specific rooms, or in properties that already have separate hot water (e.g. an immersion heater or solar thermal).
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Air Source Heat Pump Running Costs
This space-heating example uses 12,000kWh of useful heat per year, a seasonal heat-pump efficiency of 3.2, and a gas boiler efficiency of 90%. It applies Ofgem’s average direct-debit unit rates for 1 July to 30 September 2026: electricity 26.11p/kWh and gas 7.33p/kWh. It excludes hot water, standing charges, servicing and installation costs. Actual bills depend on your home and tariff.
| System or scenario | Energy used for the same heat | Annual space-heating cost |
|---|---|---|
| Heat pump, standard electricity rate | 3,750kWh electricity | £979 |
| Gas boiler, 90% efficient | 13,333kWh gas | £977 |
| Heat pump, illustrative 18p/kWh average paid rate | 3,750kWh electricity | £675 |
The standard-rate examples are almost equal. The lower-rate example saves about £302 a year against this gas boiler, but 18p/kWh is an assumed average across all heat-pump consumption, not a supplier offer. A cheap overnight or midday window does not make every unit that price. Compare the whole tariff, including peak periods and household electricity use.
For the full calculation, including a separate hot-water example, see our heat pump running-cost guide. The source rates are on Ofgem’s unit-rate table.
BUS Grant and Other Heat Pump Funding
The Boiler Upgrade Scheme (BUS) provides £7,500 towards an air-to-water heat pump – rising to £9,000 for off-gas-grid homes replacing oil or LPG between 21 July 2026 and 31 March 2027 – or £2,500 for air-to-air units. The scheme now runs until 2030 and the grant is deducted from your installer’s quote.
The BUS grant is the main financial incentive for heat pump installations in England and Wales. It’s administered by Ofgem and must be applied for by an MCS-certified installer – you cannot claim it yourself. Here’s the full breakdown of available funding across the UK:
| Grant/Scheme | Amount | Eligibility | End Date |
|---|---|---|---|
| BUS – Air-to-Water ASHP | £7,500 | England & Wales, replacing fossil fuel | 2030 |
| BUS – Off-gas uplift (oil/LPG) | £9,000 | England & Wales, off-gas homes replacing oil or LPG (air-to-water or ground source) | 21 Jul 2026 – 31 Mar 2027 |
| BUS – Air-to-Air ASHP | £2,500 | England & Wales, replacing fossil fuel | 2030 |
| BUS – Biomass Boiler | £5,000 | Rural/off-gas grid only | 2030 |
| Home Energy Scotland | Up to £7,500 grant + £7,500 loan | Scottish homeowners | Ongoing |
| Warmer Homes Scotland | Up to £10,000 | Low-income Scottish households | Ongoing |
| Warm Homes Wales (Nest) | Fully funded (no published cap) | Low-income Welsh households | Ongoing |
| ECO4 | Up to 100% of cost | Low-income households, England | 31 December 2026 |
BUS Grant Eligibility Checklist
To qualify for the BUS grant, your installation must meet all of these criteria:
- You must own the property (landlords qualify for rented properties)
- The heat pump must replace an existing fossil fuel heating system (gas, oil, LPG, or electric)
- You no longer need a valid EPC to qualify – this requirement was removed for applications from 28 April 2026
- The installer must be MCS-certified and registered with the TrustMark scheme
- Most new builds are excluded, but eligible self-builds and some finished new builds can qualify. Check the current property rules before ruling a home in or out.
The grant is applied as a discount on your installer’s invoice. You don’t receive cash – the installer claims it from Ofgem after the work is completed. Combined with the current 0% VAT rate (until March 2027), a 3-bed home can realistically get a heat pump installed for £1,500-£4,500 out of pocket.
Additional Installation Costs
Beyond the heat pump unit, budget £500-£9,000 for extras like radiator upgrades, a hot water cylinder, underfloor heating, or an electrical supply upgrade.
The headline installation cost covers the heat pump unit, outdoor mounting, pipework, and commissioning. But several common extras can add to the total, especially if your home hasn’t been adapted for low-temperature heating:
| Additional Work | Cost | When Needed |
|---|---|---|
| Radiator upgrades | £3,600 – £9,000 | If existing radiators are too small for low-temp flow (35-45°C) |
| Hot water cylinder | £500 – £1,500 | Replacing a combi boiler (which has no cylinder) |
| Underfloor heating (per floor) | £2,000 – £5,000 | Optional – ideal pairing for heat pumps (higher COP at lower temps) |
| Electrical supply upgrade | £500 – £1,000 | Older homes with undersized consumer units |
Radiator upgrades are the most common additional cost. Heat pumps run at lower flow temperatures (35-45°C) than gas boilers (60-80°C), which means you may need larger radiators to emit the same amount of heat. An MCS installer will calculate whether your existing radiators are adequate. In well-insulated homes with modern radiators, upgrades often aren’t needed.
Underfloor heating is the ideal companion for a heat pump. Because UFH operates at 35°C – exactly matching a heat pump’s most efficient output temperature – the combination delivers a COP of 4.0+ in well-insulated homes. If you’re renovating anyway, the additional cost pays for itself through lower running costs.
Heat Pump Brand Comparison
Samsung, Daikin, Vaillant, and Hitachi are the most popular ASHP brands in the UK, with supply-only prices ranging from £3,000 for a Samsung to £10,000+ for a premium Vaillant.
| Brand | Supply-Only Price | Strengths | Best For |
|---|---|---|---|
| Samsung EHC Monobloc | £3,000 – £7,000 | Competitive price, reliable, quiet operation | Budget-conscious homeowners |
| Hitachi Yutaki M | £4,000 – £7,000 | High COP (up to 5.0), compact outdoor unit | Smaller properties, tight spaces |
| Daikin Altherma | £6,000 – £10,000 | Extensive installer network, proven track record, quiet | Larger homes, underfloor heating |
| Vaillant flexoTHERM | £7,000 – £10,000 | Premium build quality, smart controls, high efficiency | Premium installations, integrating with solar PV |
All four brands are MCS-approved and eligible for the BUS grant. Warranties typically range from 5 to 12 years depending on the model and whether the installer offers extended cover. Always check that your installer is an authorised dealer for the brand they recommend – this ensures warranty validity and access to manufacturer support.
Budget brands like Samsung offer the lowest upfront cost, but premium brands like Daikin and Vaillant often deliver higher seasonal efficiency (meaning lower running costs over the 20-year lifespan). The “best” brand depends on your property, budget, and whether you prioritise upfront savings or long-term efficiency.
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Heat Pump Payback Period
Calculate payback from the extra upfront cost of the heat pump compared with the alternative you would actually buy. Divide that difference by the annual saving after allowing for servicing and any changes to standing charges. If there is no annual saving, there is no running-cost payback.
Illustration: a £12,000 installation less a £7,500 grant leaves £4,500 to pay. If the alternative boiler quote is £3,500, the extra investment is £1,000. With the illustrative £302 annual saving above, simple payback is about 3.3 years. At the standard-rate result above, there is no saving to repay that extra investment. These are assumptions, not typical quotes or a prediction.
If you are keeping a working boiler instead, the comparison changes because you are not avoiding a replacement purchase. Use your own quotes, annual heat demand and realistic seasonal efficiency. For oil or LPG, use recent delivered fuel prices and the existing system’s efficiency rather than a generic national saving.
Heat Pump Maintenance Costs
Annual heat pump servicing costs £150-£300, with a typical lifespan of 20 years. Repairs average £500 but range from £150 for minor fixes to £2,000 for compressor replacement.
Heat pumps have fewer moving parts than gas boilers (no combustion, no flue, no gas valve), which means they’re generally cheaper to maintain. An annual service is recommended to maintain efficiency and warranty validity.
| Maintenance Item | Cost | Frequency |
|---|---|---|
| Annual service | £150 – £300 | Yearly |
| Typical repair | £500 | As needed |
| Compressor replacement | £1,000 – £2,000 | Rare (usually under warranty) |
| Refrigerant recharge | £150 – £400 | If pressure drops (leak repair separate) |
Over a 20-year lifespan, total maintenance costs are typically £3,000-£6,000 – comparable to a gas boiler. The key difference is that heat pumps don’t require a Gas Safe engineer, and there’s no annual gas safety certificate to arrange. Most manufacturers offer extended warranties (up to 12 years) that cover compressor and parts failures.
Is an Air Source Heat Pump Worth It?
An air source heat pump is worth it if you’re replacing an old, inefficient boiler or off-gas heating (oil, LPG, electric). It’s harder to justify against a working new gas boiler purely on running costs.
The decision depends on your current heating system, home insulation, and time horizon. Here’s a clear framework:
Strong case for a heat pump:
- Your boiler is 15+ years old and due for replacement anyway
- You’re on oil, LPG, or electric heating (immediate running cost savings)
- Your home is reasonably well insulated (EPC band C or above)
- You have underfloor heating or are willing to upgrade radiators
- You plan to stay in the property for 10+ years
- You want to reduce your carbon footprint (roughly 60-70% lower emissions than gas on the current UK grid, and improving as it decarbonises)
Weaker case for a heat pump:
- You have a new, efficient gas boiler that’s working well
- Your home has poor insulation and you can’t or won’t upgrade it
- You plan to move within the next 5 years
- You’re only motivated by running cost savings (the case is marginal vs mains gas at today’s prices)
Future energy prices are uncertain. Base the decision on current quotes and a range of running-cost scenarios, rather than assuming electricity prices or property values will move in your favour.
How to Get the Best Price on a Heat Pump
Get at least three quotes from MCS-certified installers, confirm BUS grant eligibility before signing, and check that the quote includes all ancillary costs like cylinder and radiator upgrades.
Heat pump prices vary significantly between installers – it’s common to see £3,000-£5,000 differences for the same property. Follow these steps to ensure you get the best value:
- Get 3+ quotes from MCS-certified installers. Only MCS installers can apply for the BUS grant on your behalf. Check the MCS Installer Lookup tool to find certified companies in your area.
- Ensure the quote includes a heat loss survey. A reputable installer won’t recommend a system size without measuring your home’s actual heat loss. Be wary of quotes based on floor area alone.
- Check what’s included. Does the price cover the BUS grant application, cylinder, controls, radiator upgrades (if needed), electrical work, and commissioning? Get an all-in price.
- Ask about the brand and warranty. A 5-year warranty is standard; premium installers offer 7-12 years. Check the installer is an authorised dealer for the brand.
- Time your installation. Spring and summer are the best times to install (lower demand, faster scheduling, and you’re not without heating during installation).
Use our free quote comparison tool to receive up to 3 tailored quotes from MCS-certified installers in your area. There’s no obligation and it takes less than 2 minutes.
