Air-to-Air Heat Pump Cost UK: Installation & Running Costs
Last updated: August 2026
Air-to-air heat pumps can provide both heating and cooling without radiators or wet central heating. But how much does a complete system cost, how expensive is it to run, and does the new £2,500 Boiler Upgrade Scheme grant make it a realistic alternative to a conventional air source heat pump?
This guide explains UK air-to-air heat pump installation costs, multi-room systems, running-cost calculations, grant eligibility, hot-water implications and the factors that determine whether the system makes financial sense for your home.
• Independent UK heat pump researcher
• Reviewed for accuracy
Quick Answer: How Much Does an Air-to-Air Heat Pump Cost?
There is no reliable single UK price for an air-to-air heat pump because the cost depends heavily on how many rooms need heating, how many indoor units are required and whether the system is being installed as supplementary heating or designed to meet the whole property’s heat demand.
A simple one-room split installation can cost a few thousand pounds, while a properly designed multi-room or whole-home system can run into several thousand pounds and potentially exceed £10,000 for larger or more complex properties.
| System | Broad Planning Range | Typical Use |
|---|---|---|
| Single-room split | Approx. £1,500–£3,000 | One bedroom, office or living area |
| Small multi-split | Approx. £3,000–£6,000+ | Two or three rooms |
| Larger multi-room system | Approx. £6,000–£10,000+ | Several rooms / substantial heating coverage |
| Complex whole-home system | Potentially £10,000+ | Larger homes or complex layouts |
These are broad planning ranges rather than fixed market prices. Air-to-air heat-pump pricing is still less standardised in the UK domestic market than conventional air-to-water heat-pump pricing, and the final cost depends heavily on the design.
The £2,500 grant can change the calculation
Eligible residential air-to-air heat-pump installations in England and Wales can currently receive £2,500 through the Boiler Upgrade Scheme.
However, this is not a general discount for installing reversible air conditioning. The system and property must satisfy the Boiler Upgrade Scheme requirements.
If you are still deciding whether air-to-air is the right technology rather than simply comparing cost, start with our Air-to-Air Heat Pumps UK guide.
What Are You Actually Paying For?
An air-to-air heat pump is not simply an outdoor unit attached to an indoor fan.
A complete installation can include:
- One or more outdoor heat-pump units
- Indoor units for the rooms or zones being heated
- Refrigerant pipework
- Insulation around refrigerant lines
- Condensate drainage
- Electrical supplies and isolators
- Control equipment
- Wall penetrations
- Trunking or other pipework finishing
- Mounting brackets or bases
- Pressure testing
- Commissioning
If the installation is intended to replace the main heating system, there is another important cost: proper heating design.
The system needs enough capacity and suitable indoor-unit coverage to meet the heating requirement of the rooms it is expected to serve.
Our complete Air-to-Air Heat Pumps UK guide explains whole-home layouts, indoor-unit choices and single-split vs multi-split design in more detail.
Why Does Air-to-Air Heat Pump Installation Cost Vary So Much?
The biggest cost difference is usually between installing one unit as supplementary heating and designing a system to heat an entire home.
Number of indoor units
A single open-plan living area might only require one appropriately selected indoor unit. A traditional UK house with separate bedrooms, hallways and closed doors may require considerably more.
Number of outdoor units
Several indoor units can sometimes connect to one multi-split outdoor unit, but one large outdoor unit is not automatically the best design for every property.
Pipe routes
Short pipework through the wall directly behind an indoor unit is much easier than routing refrigerant lines between floors or across several parts of a finished property.
Condensate drainage
Indoor units produce condensate during cooling. Gravity drainage is preferable where practical, but some installations may require pumps or more complicated drainage routes.
Electrical work
Additional electrical work may be required depending on the equipment, existing supply and installation design.
Indoor-unit style
Wall-mounted units are only one option. Floor-mounted, ceiling cassette and concealed ducted equipment can alter both the appearance and cost of an installation.
If cooling is your primary goal rather than whole-home heating, our Home Air Conditioning UK guide explains these system types from a cooling-first perspective.
Single-Split vs Multi-Split Air-to-Air Heat Pump Costs
Single-Split
One outdoor unit connects to one indoor unit.
Usually best suited to:
- One bedroom
- Home office
- Garden room
- Loft conversion
- Open-plan living space
It is normally the simplest fixed air-to-air installation.
Multi-Split
Several indoor units connect to an outdoor unit, subject to the equipment design.
Usually best suited to:
- Several bedrooms
- Multi-room heating and cooling
- Homes trying to reduce outdoor-unit numbers
- More substantial air-to-air heating systems
The installation becomes more complex as the number of rooms and pipe routes increases.
Do not assume multi-split is automatically cheaper than using several smaller systems. The right arrangement depends on equipment capacity, diversity of demand, pipe lengths, property layout and how independently different rooms need to operate.
For the wider practical differences between these system layouts, see the Air-to-Air Heat Pumps UK guide.
How Much Does a Whole-House Air-to-Air Heat Pump Cost?
This is where air-to-air pricing becomes difficult to reduce to a simple national average.
Unlike an air-to-water heat pump, where one outdoor unit normally supplies a central water circuit, an air-to-air system has to distribute warm air to the spaces being heated.
In a traditional UK home with several enclosed rooms, that can mean multiple indoor units.
A whole-home design could use:
- Several single-split systems
- One or more multi-split systems
- Concealed ducted equipment
- A combination of different indoor-unit types
For larger multi-room installations, a planning budget of several thousand pounds is realistic, and more extensive systems can exceed £10,000.
A lower-cost proposal is not necessarily better value if parts of the property cannot be heated adequately. If air-to-air is intended to become your main heating system, the design should reflect the home’s room-by-room heating requirement rather than simply putting units wherever installation is easiest.
If you are comparing this with conventional whole-house air conditioning rather than a replacement heating system, see our Air Conditioning Cost UK guide.
Can You Get the £2,500 Air-to-Air Heat Pump Grant?
Yes, potentially. The Boiler Upgrade Scheme currently provides £2,500 towards eligible residential air-to-air heat-pump installations in England and Wales.
Ofgem administers the scheme and the application is installer-led through an MCS-certified installer.
However, the eligibility requirements are particularly important for air-to-air systems.
It isn’t a £2,500 air-conditioning voucher
Simply installing a reversible split air conditioner does not automatically mean you qualify for the grant.
For BUS, the heat pump must satisfy the scheme requirements, including being sized to meet the property’s full space-heating needs.
For a retrofit property, the BUS-funded installation generally needs to:
- Be at an eligible property in England or Wales
- Be a residential property for an air-to-air installation
- Replace an existing fossil-fuel or electric heating system
- Not replace an existing low-carbon heating system
- Be installed through an appropriately MCS-certified installer
- Meet the relevant technical and efficiency requirements
- Be sized to meet the property’s full space-heating requirement
That last point is crucial.
If you add one reversible split unit to a bedroom while retaining your existing boiler as the main heating system, you should not assume that installation qualifies for £2,500 BUS support.
Read our Heat Pump Grants UK guide for the wider Boiler Upgrade Scheme rules.
What Could an Air-to-Air Heat Pump Cost After the £2,500 Grant?
Where an installation qualifies, the grant reduces the eligible upfront installation cost by £2,500.
| Example Eligible Quote | BUS Grant | Remaining Cost |
|---|---|---|
| £5,000 | £2,500 | £2,500 |
| £7,500 | £2,500 | £5,000 |
| £10,000 | £2,500 | £7,500 |
| £12,000 | £2,500 | £9,500 |
These are simply arithmetic examples showing how the grant affects an eligible quote. They are not typical installation prices and do not imply that a system at any of these prices will qualify.
The BUS grant should be passed on by the installer as an upfront discount rather than treated as money you claim back afterwards.
For the latest eligibility rules alongside other heat-pump grants, see Heat Pump Grants UK.
Does the £9,000 Off-Gas-Grid Heat Pump Grant Apply to Air-to-Air?
No.
From 21 July 2026, the Boiler Upgrade Scheme offers an increased £9,000 grant for qualifying off-gas-grid properties replacing eligible oil or LPG heating.
However, that uplift applies to eligible air-to-water and ground source heat pumps, not air-to-air heat pumps. Ofgem’s current guidance explicitly limits the uplifted grant to these technologies. citeturn700153search0turn700153search14
The current BUS support for an eligible residential air-to-air heat pump remains £2,500.
This distinction is important for off-grid homeowners comparing technologies. A conventional air-to-water heat pump may receive substantially more upfront support than an air-to-air system.
If this applies to your home, compare both approaches in our Heat Pump vs Air Conditioning UK guide rather than choosing on pre-grant installation price alone.
How Much Does an Air-to-Air Heat Pump Cost to Run?
Air-to-air heat pumps run on electricity, but they do not work like ordinary electric resistance heaters.
Instead of turning one unit of electricity directly into approximately one unit of heat, a heat pump uses electricity to move heat from outside air into the home.
The basic running-cost relationship is:
Heating cost calculation
Heat required ÷ heat-pump efficiency × electricity price = approximate heating energy cost
The challenge is that heat-pump efficiency is not fixed.
It changes with:
- Outdoor temperature
- Indoor target temperature
- Equipment specification
- Part-load operation
- Defrost cycles
- System sizing
- Controls
- Installation quality
For this reason, annual or seasonal efficiency is usually more useful for estimating heating costs than looking at one impressive COP figure measured under a single test condition.
For a wider explanation of how air-to-air systems behave in cold weather and what COP and SCOP mean, see our Air-to-Air Heat Pumps UK guide.
Air-to-Air Heat Pump Running Cost Examples
Ofgem’s current average electricity unit rate for a Direct Debit household on the standard variable price cap is 26.11p/kWh for 1 July to 30 September 2026. citeturn700153search3
Your own tariff may be different.
To illustrate how efficiency changes the calculation, imagine a home needs 10,000kWh of useful space heat over a period.
| Illustrative Seasonal Efficiency | Electricity Required | Cost at 26.11p/kWh |
|---|---|---|
| 2.5 | 4,000kWh | Approx. £1,044 |
| 3.0 | 3,333kWh | Approx. £870 |
| 3.5 | 2,857kWh | Approx. £746 |
| 4.0 | 2,500kWh | Approx. £653 |
These are illustrative calculations, not predictions of your bill.
The table assumes exactly 10,000kWh of useful space-heating demand and uses simplified seasonal efficiency figures purely to demonstrate the relationship between efficiency and electricity cost.
Your home’s heat demand, system efficiency and electricity tariff could all be different.
For the broader methodology behind heat-pump running-cost estimates, see our Heat Pump Running Costs UK guide.
Why Air-to-Air Can Be Efficient for Space Heating
Air-to-air systems transfer heat directly into room air.
They do not need to heat water and circulate it through radiators before that heat reaches the room.
This can allow efficient space heating, particularly where:
- The system is correctly sized
- Indoor units are positioned well
- Rooms have suitable heat-loss characteristics
- The equipment can operate steadily rather than repeatedly switching on and off
- Temperature settings are sensible
However, high equipment efficiency does not automatically mean low household bills. A poorly insulated home still needs more heat, and an expensive electricity tariff can materially change the financial comparison.
Air-to-Air Heat Pump vs Gas Boiler Running Costs
This comparison is less straightforward than simply comparing electricity and gas unit prices.
Under the July–September 2026 Ofgem price cap, the average Direct Debit rates are:
- Electricity: 26.11p/kWh
- Gas: 7.33p/kWh
Electricity therefore costs considerably more per purchased kWh, but a heat pump can deliver multiple units of useful heat for each unit of electricity consumed.
A gas boiler, meanwhile, cannot convert every purchased kWh of gas into useful room heat.
Why there is no universal winner
The result depends on the heat pump’s seasonal efficiency, the boiler’s real efficiency, your tariffs, the home’s heat requirement and how both systems are operated.
For that reason, we do not claim that an air-to-air heat pump will automatically be cheaper than mains gas.
The financial case can be more attractive where air-to-air replaces expensive direct electric heating, while gas comparisons need more careful calculation.
If you are comparing the complete replacement of a conventional central-heating system, see our Heat Pump vs Air Conditioning UK comparison.
Air-to-Air Heat Pump vs Direct Electric Heating Costs
This is one of the most straightforward comparisons.
A conventional electric panel heater, fan heater or similar resistance heater largely converts purchased electricity directly into heat at the point of use.
An air-to-air heat pump instead uses electricity to transfer additional heat from outside.
If both systems buy electricity at the same tariff, a properly operating heat pump can therefore require substantially less electricity to deliver the same amount of useful space heat.
Actual savings still depend on the system, property and usage, but homes currently relying heavily on direct electric space heating are particularly relevant candidates for air-to-air technology.
For more on which property types suit this approach, see our Air-to-Air Heat Pumps UK guide.
What About Oil and LPG Heating?
Air-to-air can also be relevant to off-grid homes currently using oil or LPG.
However, the decision should not be based on running cost alone.
As of July 2026, qualifying off-gas-grid properties replacing oil or LPG can receive an enhanced £9,000 BUS grant towards eligible air-to-water or ground source heat pumps. citeturn700153search4turn700153search11
Air-to-air does not receive that enhanced grant.
So an off-grid homeowner needs to compare:
- Air-to-air installation cost
- The £2,500 air-to-air grant if eligible
- Air-to-water installation cost
- Potential £9,000 off-grid air-to-water support if eligible
- Radiator and cylinder requirements
- Expected running costs
- Cooling requirements
- Domestic hot-water provision
That is a good example of why the cheapest technology before grants may not be the cheapest overall option after current government support.
See our Heat Pump Grants UK guide for current support and Heat Pump vs Air Conditioning UK for the wider technology comparison.
The Hidden Cost: Air-to-Air Does Not Normally Provide Hot Water
This is one of the biggest differences between an air-to-air heat pump and the air-to-water systems commonly installed to replace UK boilers.
An air-to-water heat pump can normally be designed to provide:
- Space heating
- Domestic hot water
A conventional air-to-air system heats the air in your rooms. It does not normally heat the water in your hot-water cylinder or taps.
You therefore need a separate hot-water solution.
Depending on the property, that might include:
- An existing suitable hot-water arrangement
- Direct electric hot-water heating
- A dedicated heat-pump water heater
- Another compatible low-carbon hot-water solution
A cheaper space-heating installation can lose some of its financial advantage if you also need to invest in a new domestic hot-water system. Always compare the total heating-and-hot-water solution.
Our Air-to-Air Heat Pumps UK guide looks at the practical hot-water options in more detail.
Does Air-to-Air Need New Radiators?
No. Air-to-air heat pumps do not use radiators to distribute heat.
This can avoid one of the potential upgrade costs associated with moving from a boiler to an air-to-water heat pump.
Instead, heat is delivered directly into rooms through indoor fan units or a suitable ducted distribution system.
That does not mean the installation is automatically simpler.
The trade-off is that you need to consider:
- How many indoor units are required
- Where they will be positioned
- How heat reaches closed rooms
- Refrigerant pipe routes
- Condensate drainage
- Indoor airflow
- Appearance
- Fan noise
If radiator replacement is an important part of your air-to-water quote, see our heat pump radiator guide for the alternative system costs and design implications.
Air-to-Air vs Air-to-Water Heat Pump Cost
Air-to-air can have a lower-cost route into heat-pump heating because it does not require a new wet heating circuit, larger radiators or the same type of hot-water cylinder installation.
But the comparison becomes less simple when government support and whole-home requirements are included.
| Cost Factor | Air-to-Air | Air-to-Water |
|---|---|---|
| Heat distribution | Indoor fan units / ducts | Radiators / underfloor heating |
| Radiator upgrades | Not required | May be required |
| Hot-water provision | Usually separate | Can be integrated |
| Cooling | Major advantage of reversible systems | Not normally the core function of typical UK installations |
| Standard BUS support | £2,500 if eligible | £7,500 if eligible |
| Eligible off-grid BUS uplift | Not available | Up to £9,000 under current rules |
Air-to-air can therefore be particularly attractive where cooling is valuable, the home does not already have a suitable wet heating system, or avoiding radiator upgrades is important.
Air-to-water may be more attractive where the homeowner wants a familiar central-heating arrangement, integrated domestic hot water or can benefit from substantially higher grant support.
Can Solar Panels Reduce Air-to-Air Heat Pump Running Costs?
Solar PV can potentially supply some of the electricity used by an air-to-air heat pump when solar generation and heat-pump demand occur at the same time.
The overlap can be particularly useful for summer cooling, because air-conditioning demand often coincides with periods of strong solar generation.
Winter heating is different. Solar generation is lower and much of the heating demand occurs early in the morning, evening or during dull weather.
So solar panels can reduce imported electricity, but they should not be assumed to make winter heating free.
What Affects Air-to-Air Heat Pump Running Costs?
Property heat loss
A home that loses heat quickly requires more energy to maintain the same indoor temperature.
Outdoor temperature
Heating demand generally increases during colder weather, while heat-pump operating conditions also become more demanding.
Indoor temperature
Higher target temperatures increase the amount of heat the system needs to supply.
System sizing
Equipment should be selected around the heating requirement of the property and rooms being served.
Indoor-unit placement
Good equipment in a poor location can struggle to distribute heat comfortably.
Controls
Multi-room systems can provide useful zoning, but control strategy affects both comfort and energy consumption.
Electricity tariff
Heat-pump efficiency determines how much electricity you need; your tariff determines what that electricity costs.
Installation quality
Correct refrigerant charging, commissioning, airflow and system setup all matter to real-world operation.
For wider heat-pump running-cost methodology, see our Heat Pump Running Costs UK guide.
Is an Air-to-Air Heat Pump Cheaper Than Air Conditioning?
This question sounds logical, but in many cases you are comparing the same underlying technology used for different purposes.
Many modern fixed split air-conditioning systems are reversible heat pumps.
The important difference is therefore often not:
Air conditioning vs air-to-air heat pump
but:
A system installed mainly for cooling vs a system designed to meet the home’s heating requirement.
A one-room AC installation may be relatively inexpensive but cannot automatically replace central heating.
A whole-home air-to-air heating system needs sufficient output and distribution throughout the property, which can significantly increase the installation cost.
If you are pricing cooling rather than a heating-system replacement, see our Air Conditioning Cost UK guide.
Is an Air-to-Air Heat Pump Worth the Cost?
Air-to-air is particularly interesting because one investment can potentially solve two problems: winter heating and summer overheating.
Air-to-Air May Be Worth Considering If…
- You want both heating and cooling
- You currently use direct electric heating
- Your home does not have wet central heating
- You want room-by-room control
- You want to avoid radiator upgrades
- You have suitable locations for indoor and outdoor units
Compare Carefully If…
- You already have inexpensive mains-gas heating
- You dislike visible indoor fan units
- Your home has many small enclosed rooms
- You also need a new hot-water solution
- You qualify for much higher support towards air-to-water
- Cooling has little value to you
There is no universal answer. The right comparison is the total installed cost, grant support, hot-water provision, expected running costs and usefulness of cooling for your particular home.
If you are still choosing between the technologies rather than simply pricing air-to-air, read our Heat Pump vs Air Conditioning UK guide.
What Should You Ask for in an Air-to-Air Heat Pump Quote?
If the system is intended to become your main heating system, ask for more than a list of air-conditioning units.
- What is the calculated heating requirement of the property?
- How was each indoor unit sized?
- Can the proposed system meet the heating requirement in cold weather?
- Which rooms will have indoor units?
- How will rooms without an indoor unit be heated?
- What are the exact indoor and outdoor unit models?
- What seasonal efficiency data applies?
- What are the indoor and outdoor sound levels?
- Where will refrigerant pipework run?
- How will condensate be drained?
- What electrical work is included?
- How will domestic hot water be provided?
- Is the proposal eligible for the £2,500 BUS grant?
- Is the installer appropriately MCS certified for the grant application?
- What maintenance and warranty requirements apply?
Use our Air-to-Air Heat Pumps UK guide alongside this checklist if you want more detail on indoor-unit layouts, cold-weather performance, hot water and whole-home design.
Air-to-Air Heat Pump Cost FAQs
How much does an air-to-air heat pump cost in the UK?
A simple single-room split installation can cost a few thousand pounds, while larger multi-room and whole-home systems can cost several thousand pounds and potentially more than £10,000. The final price depends heavily on the number of rooms, equipment, pipe routes, electrical work and installation design.
Can I get £2,500 towards an air-to-air heat pump?
Eligible residential air-to-air heat-pump installations in England and Wales can currently receive £2,500 through the Boiler Upgrade Scheme. The system must satisfy the scheme requirements, including being sized to meet the property’s full space-heating needs.
Can I get the £2,500 grant for normal air conditioning?
Do not assume so. Reversible air-conditioning equipment may use air-to-air heat-pump technology, but BUS eligibility depends on the complete installation satisfying the scheme rules. Adding supplementary AC to one room is not automatically an eligible whole-home heating installation.
Does the £9,000 off-grid heat pump grant apply to air-to-air?
No. The current £9,000 BUS uplift for qualifying off-gas-grid properties applies to eligible air-to-water and ground source heat pumps, not air-to-air heat pumps.
Is an air-to-air heat pump cheap to run?
It can provide efficient space heating because it transfers heat rather than relying on direct electric resistance. Actual running costs depend on the property’s heat requirement, seasonal system efficiency, electricity tariff, weather, controls and usage.
Is air-to-air cheaper to run than gas?
Not automatically. Electricity costs substantially more per kWh than gas, but a heat pump can deliver multiple units of useful heat from each unit of electricity. The result depends on heat-pump efficiency, boiler efficiency, tariffs and the property’s heating demand.
Does an air-to-air heat pump provide hot water?
A conventional air-to-air system normally provides space heating and cooling rather than domestic hot water. A separate hot-water solution therefore needs to be included when comparing whole-home system costs.
Do air-to-air heat pumps need radiators?
No. They deliver heat directly into rooms through indoor fan units or suitable ductwork rather than circulating heated water through radiators.
Installation and running costs vary considerably. Air-to-air performance depends on property heat loss, system design, equipment sizing, outdoor temperature, indoor-unit placement, controls, installation quality, usage and electricity tariff. Grant rules can also change. Use the figures in this guide for comparison and planning rather than as guaranteed prices or savings.
Sources & Further Reading
This guide uses current Ofgem and UK government information for Boiler Upgrade Scheme support, energy prices and the domestic performance of reversible air-to-air heat pumps.
Related Guides
Air-to-Air or a Conventional Heat Pump?
Air-to-air can avoid radiators and provide summer cooling, while air-to-water can integrate with central heating and domestic hot water and currently receives substantially more BUS support. Compare the complete systems before deciding.