Air source heat pumps (ASHPs) are the UK’s fastest-growing home heating technology – but they represent a significant investment. This guide breaks down every cost you need to budget for in 2026, from the unit price and installation labour to running costs, grants, and long-term payback. All figures are cross-referenced against five leading UK sources and verified against Ofgem’s Q3 2026 price cap rates.
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.
Leading manufacturers include Vaillant, Daikin, Mitsubishi, and Samsung, with the Vaillant Arotherm Plus consistently rated among the most efficient models at a coefficient of performance (COP) of 4.0-5.0. Running costs average £900-£1,100 per year for a typical three-bedroom house on the standard tariff – close to mains gas in well-insulated properties, and lower still on a specialist heat pump tariff. Homes with an EPC rating of D or below may need insulation upgrades before a heat pump operates efficiently, potentially adding £1,000-£5,000 to the overall project cost.
Leading brands – Mitsubishi Ecodan, Vaillant aroTHERM, Daikin Altherma, and Samsung – are all MCS-certified and BUS-eligible. At Ofgem’s Q3 2026 electricity price cap of 26.11p/kWh, a heat pump with a COP of 3.0 delivers heat at roughly 8.7p/kWh – close to parity with a new gas boiler now that gas costs 7.33p/kWh. Air-to-air systems cost less at £4,000–£9,500 but cannot connect to existing radiator circuits. Energy rates and grant levels verified July 2026 against Ofgem and GOV.UK; installation prices verified February 2026 against five installer networks.
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- Average installed cost for a 3-bed semi is £9,000-12,000 before the BUS grant - ranges from £7,000 for budget brands (Samsung, LG) to £17,000 for premium systems (Vaillant, Nibe) including installation
- After the £7,500 Boiler Upgrade Scheme grant, out-of-pocket cost drops to £1,500-4,500 - comparable to a premium gas boiler installation, with the grant covering 50-80% of total cost
- Running costs are £700-1,200/year depending on tariff and insulation level - specialist heat pump tariffs (7-10p/kWh) cut this to £500-700, cheaper than gas at current Ofgem cap rates
- Installation typically takes 2-3 days and includes radiator upgrades if needed - budget £1,500-3,000 for radiator upsizing in older properties not designed for low-temperature heating
- Payback period is 6-10 years when replacing oil or LPG, 12-15 years when replacing gas - the £7,500 grant shortens payback by 3-5 years compared to the pre-2025 £5,000 grant level
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
An air source heat pump costs £675-£1,345 per year to run, depending on property size. At current electricity prices, a well-insulated 3-bed home pays around £1,010 annually.
Running costs depend on electricity prices, your home’s insulation, and the heat pump’s efficiency (measured as Coefficient of Performance, or COP). A COP of 3.0 means the pump produces 3 kWh of heat for every 1 kWh of electricity used. For a full breakdown including tariff comparisons, see our dedicated heat pump running costs guide.
| Property Size | Annual Heating Demand | ASHP Running Cost |
|---|---|---|
| 2-bed terrace | ~8,000 kWh | £675/year |
| 3-bed semi-detached | ~12,000 kWh | £1,010/year |
| 4-bed detached | ~16,000 kWh | £1,345/year |
These figures use the Ofgem Q3 2026 (July–September) price cap rate of 26.11p/kWh for electricity and assume an average seasonal COP of 3.1. Actual performance varies with outdoor temperature – ASHPs work harder (and less efficiently) in very cold weather, though modern units maintain a COP above 2.0 even at −10°C. For northern cities like Manchester, where winters are colder and wetter, expect seasonal COP closer to 2.8-3.0.
Heat Pump vs Gas Boiler Running Costs
At current energy prices (electricity 26.11p/kWh, gas 7.33p/kWh under the Q3 2026 Ofgem cap), a heat pump with a COP of 3.1 produces heat at roughly the same cost per kWh as a new A-rated gas boiler. The effective cost per kWh of heat is:
- Heat pump at COP 3.1: 26.11p ÷ 3.1 = 8.42p per kWh of heat
- New A-rated gas boiler (92% efficient): 7.33p ÷ 0.92 = 7.97p per kWh of heat
- Old G-rated gas boiler (70% efficient): 7.33p ÷ 0.70 = 10.47p per kWh of heat
This means a heat pump currently costs roughly £100-£130 more per year than a new gas boiler – but saves £290/year compared to an old G-rated boiler. Against oil heating, savings are around £260/year. Against LPG, savings reach £630/year. Against electric storage heaters, you’ll save over £1,000/year.
| Heating System | Annual Cost (3-bed) | Saving vs ASHP |
|---|---|---|
| Air source heat pump (COP 3.1) | £1,010 | – |
| New A-rated gas boiler | £955 | +£55 cheaper |
| Old G-rated gas boiler | £1,255 | £245 saving |
| Oil boiler | £1,270 | £260 saving |
| LPG boiler | £1,640 | £630 saving |
| Electric storage heaters | £2,050 | £1,040 saving |
At a COP of 3.1, heat pumps break even with mains gas on running costs. At COP 4.0+ (achievable with underfloor heating and good insulation), they become cheaper. They’re already significantly cheaper than oil, LPG, and electric heating.
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) | Up to £5,000 | Low-income Welsh households | Ongoing |
| ECO4 | Up to 100% of cost | Low-income households, England | March 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
- New builds do not qualify – the property must already be occupied
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
After the BUS grant, an air source heat pump pays for itself in roughly 6-12 years when replacing an old gas or oil boiler, and faster still for LPG or electric heating – especially for off-gas oil/LPG homes, where the temporary £9,000 grant cuts the net cost to around £3,000 or less. Against a new gas boiler, it is unlikely to pay back on running costs alone.
Payback depends entirely on what system you’re replacing. The bigger the gap between your old fuel costs and the heat pump’s running costs, the faster you’ll recoup your investment:
| Replacing | Annual Saving | Net Cost (after BUS) | Payback Period |
|---|---|---|---|
| Old G-rated gas boiler | £245/year | £1,500 – £4,500 | 6 – 18 years |
| Oil boiler | £260/year | £0 – £3,000 (with £9,000 uplift) | Under 12 years |
| LPG boiler | £630/year | £0 – £3,000 (with £9,000 uplift) | Under 5 years |
| Electric storage heaters | £1,040/year | £1,500 – £4,500 | 2 – 4 years |
| New A-rated gas boiler | −£55/year | £1,500 – £4,500 | 14+ years* |
*Against a new gas boiler, a heat pump currently costs slightly more to run. The payback case rests on future energy price trends: if electricity falls relative to gas (as most forecasters expect with more renewables on the grid), the economics improve. A heat pump also adds property value and future-proofs your home against the 2035 gas boiler ban.
These payback figures don’t include the value of 0% VAT (saving roughly £450-£800 versus the 5% rate that returns from April 2027) or the potential property value uplift from improving your home’s EPC rating.
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 (75%+ lower emissions than gas)
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)
The financial picture is changing. The UK government’s 2035 deadline for ending new gas boiler installations, combined with rising carbon taxes on fossil fuels and falling renewable electricity costs, all point towards heat pumps becoming the cheaper option within the next decade. Installing now – while the £7,500 BUS grant and 0% VAT are available – locks in the best deal.
With the BUS grant, 0% VAT, and a 20-year lifespan, an ASHP is a sound investment for most homeowners - especially those replacing old boilers or off-gas heating. The strongest case is for well-insulated homes with underfloor heating, where a COP of 4.0+ makes running costs lower than mains gas.
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).
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