R290 Heat Pumps UK: Propane Refrigerant Explained
Last updated: August 2026
R290 heat pumps use propane as the refrigerant within the heat-pump circuit. R290 is a hydrocarbon rather than an HFC refrigerant and has a very low climate impact if released, helping explain why it is increasingly being used in modern air-to-water heat pumps.
But refrigerant choice is only one part of choosing a heat pump. This guide explains what R290 is, why propane is being adopted, its flammability and installation implications, how it relates to high-temperature heating, and what homeowners and commercial buyers should compare before choosing an R290 system.
• Independent UK heat pump researcher
• Updated for 2026
Quick Answer: What Is an R290 Heat Pump?
An R290 heat pump is a heat pump that uses propane as the refrigerant circulating through its sealed refrigeration circuit.
The refrigerant absorbs heat at a low temperature, is compressed to raise its pressure and temperature, transfers useful heat into the heating system and then returns through the refrigeration cycle.
R290 = propane
R290 is the refrigeration-industry designation for propane. It is described as a natural refrigerant and is fundamentally different from fluorinated HFC refrigerants used in many existing heat pumps and air-conditioning systems.
R290 can be used in domestic, commercial and industrial heat-pump equipment, although the design and safety requirements can differ substantially according to the type and size of system.
Why Are R290 Heat Pumps Becoming More Common?
There are several reasons propane has become increasingly important to heat-pump manufacturers and system designers.
- It has a very low global-warming impact compared with many fluorinated refrigerants.
- It is not an HFC.
- It is suitable for sealed outdoor monobloc heat-pump designs.
- It can be used in equipment designed for relatively high water temperatures.
- It reduces reliance on refrigerants affected by the HFC phase-down.
UK government work examining the future of F-gas regulation has specifically identified propane as a suitable alternative for many monobloc heat-pump applications.
What Are the Advantages of an R290 Heat Pump?
Very Low Refrigerant Climate Impact
Propane has a much lower direct greenhouse-gas impact than the high-GWP HFC refrigerants historically used across refrigeration, air conditioning and heat pumps.
Natural Refrigerant
R290 is a hydrocarbon rather than a fluorinated refrigerant and does not form part of the HFC quota being phased down in Great Britain.
High-Temperature Potential
R290 is used in a growing category of heat pumps designed to produce higher heating-water temperatures, which can be useful in some retrofit and hot-water applications.
Domestic to Commercial Scale
Propane heat-pump technology is now relevant across domestic heating, commercial buildings and larger specialist systems rather than being confined to one part of the market.
These advantages explain why R290 is important, but they do not establish whether a particular heat pump will be efficient in a particular property.
Is R290 an F-Gas?
No. R290 propane is not a fluorinated greenhouse gas.
UK F-gas rules primarily regulate fluorinated refrigerants including hydrofluorocarbons, commonly known as HFCs.
Propane is a hydrocarbon containing carbon and hydrogen rather than fluorine, so R290 is not part of the HFC refrigerant quota.
Why this distinction matters
The amount of HFC refrigerant that can be placed on the Great Britain market is being progressively reduced. Choosing R290 avoids dependence on the HFC quota, although propane introduces separate safety considerations because it is flammable.
The UK government confirmed in May 2026 that it would not legislate during 2026 to alter the HFC phase-down step already due from January 2027, while further reform is still being considered.
R290 vs R32 Heat Pumps
R290 and R32 are both used in modern heat pumps, but they are different types of refrigerant.
| Feature | R290 | R32 |
|---|---|---|
| Common name | Propane | Difluoromethane |
| Refrigerant type | Hydrocarbon | HFC |
| F-gas | No | Yes |
| Direct climate impact | Very low | Higher than R290 |
| Flammability | Highly flammable | Lower flammability than propane, but still requires appropriate refrigerant safety considerations |
| Typical UK heat-pump architecture | Particularly suited to sealed outdoor monobloc designs | Used across both monobloc and split heat-pump systems |
Why Are Many R290 Heat Pumps Monobloc Systems?
A monobloc air-to-water heat pump keeps the main refrigeration circuit within a factory-built outdoor unit.
Water connections then carry heat between the outdoor heat pump and the building’s heating system.
This architecture is particularly relevant to propane because keeping the refrigerant circuit outdoors can help manage the risks associated with a flammable refrigerant.
UK government analysis of refrigerants has identified propane as particularly suitable for monobloc heat pumps, where the refrigerant is contained in the external equipment.
Monobloc
The sealed refrigerant circuit is primarily contained within the external heat-pump unit, with water pipework entering the property.
Split System
Refrigerant pipework runs between outdoor and indoor equipment, meaning refrigerant may be present within the building.
Monobloc does not mean installation is simple. Water pipework, freeze protection, hydraulics, electrical work, controls and commissioning still need to be designed correctly.
Is R290 Refrigerant Safe?
R290 can be used safely in equipment designed and installed for propane, but it is a highly flammable refrigerant and should not be treated in the same way as a non-flammable refrigerant.
Safety measures can include:
- Limiting refrigerant charge
- Locating equipment appropriately
- Maintaining manufacturer-specified clearances
- Avoiding potential ignition sources within specified zones
- Preventing leaked refrigerant accumulating in confined spaces
- Using equipment specifically designed for R290
- Following the relevant product and installation standards
Propane is also heavier than air. This means installation guidance can restrict positioning close to features such as low-level openings, drains or confined spaces where leaking refrigerant could potentially collect.
The correct safety distances and installation requirements depend on the equipment design, refrigerant charge, location and applicable standards. Follow the current manufacturer’s installation instructions and competent installer or designer requirements for the specific system.
UK government research into air-to-air heat pumps specifically identifies the flammability of R290 and the need to prevent refrigerant accumulating in unventilated spaces.
Does an R290 Heat Pump Need a Special Installation Location?
Potentially, yes.
Because propane is flammable and heavier than air, the installation location needs to be assessed against the requirements for the particular heat pump.
Depending on equipment and installation instructions, considerations can include:
- Distance from doors and windows
- Air vents
- Light wells
- Drains
- Basement openings
- Ignition sources
- Property boundaries
- Enclosures
- Service access
This does not mean R290 heat pumps need huge exclusion zones around every installation. It means the safety requirements of the specific model and installation need to be followed rather than assumed.
R290 Heat Pumps for UK Homes
R290 is particularly relevant to modern domestic air-to-water heat pumps.
For a homeowner, the refrigerant is worth considering, but it should sit behind more important whole-system questions such as:
- Has the home’s heat loss been calculated correctly?
- What flow temperature does the property require?
- Are the radiators appropriately sized?
- What output does the heat pump deliver in cold weather?
- What seasonal efficiency is expected?
- How quiet is the outdoor unit?
- How well can it modulate at lower demand?
- What controls are provided?
- What installation and manufacturer support is available?
For actual domestic system selection, use our Best Air Source Heat Pumps UK guide.
R290 Commercial Heat Pumps
R290 is no longer relevant only to household-sized equipment. Propane is also being used in larger commercial heat-pump systems.
Potential applications include:
- Offices
- Schools
- Hotels
- Healthcare
- Retail premises
- Commercial hot-water systems
- Large central-heating systems
- Modular and cascade installations
Commercial projects can involve greater refrigerant charges and larger equipment, making risk assessment, location and system design especially important.
For the wider non-domestic market, see our Commercial Heat Pumps UK guide.
R290 Commercial Air Source Heat Pumps
Many larger R290 systems use the same basic air-to-water architecture as domestic monobloc heat pumps but at substantially greater capacities.
When comparing commercial R290 air-source equipment, investigate:
- Heating output at the project’s outdoor design temperature
- Available output at the required flow temperature
- Minimum modulation
- Cascade capability
- Defrost strategy
- Refrigerant charge
- Required safety clearances
- Noise
- Electrical input
- BMS integration
See our Commercial Air Source Heat Pumps UK guide for the wider technology and system-design considerations.
R290 and High-Temperature Heat Pumps
One reason R290 has attracted interest is its use in modern heat pumps designed to deliver relatively high heating-water temperatures.
This can potentially help with:
- Existing radiator systems
- Commercial boiler-replacement projects
- Domestic hot water
- Hotels and hospitality
- Healthcare applications
- Other higher-temperature thermal loads
But the maximum temperature a heat pump can produce is not the same thing as the temperature at which it should normally operate.
70°C or 80°C capability does not mean you should run at 70°C or 80°C
As the required temperature lift rises, heat-pump efficiency can fall. If the building can meet its heat demand at a lower flow temperature, that may still produce better seasonal performance.
Our High-Temperature Heat Pumps UK guide examines this subject in detail.
Can R290 Heat Pumps Work With Existing Radiators?
Yes, potentially — but refrigerant choice does not determine radiator compatibility.
The important question is whether the radiators can deliver enough heat at the water temperatures the proposed system will use.
For an existing property, assess:
- Room-by-room heat loss
- Existing radiator output
- Proposed flow and return temperatures
- Whether radiators need upgrading
- Whether fan-assisted emitters are appropriate
- Weather compensation
Are R290 Heat Pumps More Efficient?
Not automatically.
R290 has useful properties as a heat-pump refrigerant, but it would be misleading to claim that an R290 unit will always outperform a heat pump using another refrigerant.
Real performance depends on:
- Heat-pump design
- Compressor
- Heat exchangers
- Control strategy
- Outdoor temperature
- Flow and return temperatures
- Part-load operation
- Defrost
- Installation quality
Compare COP or seasonal figures only when the test conditions are equivalent.
A well-designed R32 system can outperform a poorly designed R290 system, and vice versa. Compare complete heat-pump performance at the conditions relevant to your home or building.
Do R290 Heat Pumps Work in Cold Weather?
Yes. R290 heat pumps are available for UK heating applications and can operate below freezing where the specific equipment is designed to do so.
However, cold-weather comparison should look at more than the manufacturer’s minimum operating temperature.
Check:
- Heating capacity at the design outdoor temperature
- COP at that temperature
- Required flow temperature
- Defrost operation
- Whether backup heat is required
A heat pump being capable of running at a very low outdoor temperature does not prove it maintains its nominal output or headline efficiency there.
R290 and Hot-Water Production
R290 is increasingly relevant to systems designed for higher-temperature water, which makes it worth considering in applications with substantial domestic hot-water demand.
But hot-water performance should still be assessed separately from space heating.
Check:
- Required cylinder temperature
- Recovery time
- Peak demand
- Storage volume
- Heat-pump output while producing hot water
- Efficiency at the required water temperature
- Legionella-control strategy
This becomes particularly important in commercial properties such as hotels, healthcare buildings and leisure facilities.
R290 in Industrial Heat Pumps
Propane is also used in larger and specialist heat-pump applications, but it is only one of several refrigerants available to the industrial market.
Industrial systems may also use technologies based on refrigerants such as CO₂ or ammonia depending on the required temperatures, capacity and process.
The industrial decision therefore starts with:
- Available heat-source temperature
- Required process temperature
- Capacity
- Temperature lift
- Operating hours
- Waste-heat availability
- Process safety requirements
For process heat and waste-heat recovery, read our Industrial Heat Pumps UK guide.
Are R290 Heat Pumps Affected by F-Gas Rules?
R290 itself is not an F-gas, so the propane refrigerant is not subject to the HFC quota in the way that HFC refrigerants are.
This does not mean R290 equipment is unregulated.
Depending on the system and application, relevant requirements can include:
- Product safety standards
- Electrical requirements
- Pressure-system requirements
- Building Regulations
- Planning requirements
- Refrigerant safety requirements
- Workplace fire and explosion risk requirements where applicable
For commercial workplaces, the use of flammable substances may also need to be considered within the organisation’s wider fire and explosion risk assessment where applicable.
What Is Happening to HFC Refrigerants in Great Britain?
Great Britain operates an HFC phase-down that progressively restricts the quantity of hydrofluorocarbon refrigerants that can be placed on the market.
Existing rules also restrict certain higher-GWP F-gases in particular types of new refrigeration, air-conditioning and heat-pump equipment.
The government consulted on further reform of the Great Britain F-gas regime and confirmed in May 2026 that it would not introduce legislation during 2026 to change the HFC phase-down step already scheduled for January 2027.
Further reform remains under consideration.
Can an R290 Heat Pump Get the Boiler Upgrade Scheme Grant?
Boiler Upgrade Scheme eligibility is based on the eligible heating technology, property and scheme requirements — not simply on whether the heat pump uses R290.
An eligible R290 air-to-water heat pump can therefore potentially qualify where the product, property, installer and installation meet the current BUS requirements.
As of August 2026, the scheme offers:
- £7,500 for qualifying air-to-water heat pumps
- £7,500 for qualifying ground-source and eligible water-source systems
- £9,000 in qualifying off-gas-grid oil or LPG replacement cases until 31 March 2027
- £2,500 for qualifying air-to-air heat pumps in residential properties only
There is no special R290 grant
Using propane rather than another refrigerant does not increase the Boiler Upgrade Scheme grant. Current technology and property eligibility rules still apply.
Are R290 Heat Pumps More Expensive?
There is no reliable rule that an R290 heat pump will always cost more or less than an equivalent system using another refrigerant.
Installed cost depends on:
- Heat-pump capacity
- System design
- Required flow temperature
- Radiator or emitter upgrades
- Hot-water cylinder
- Electrical work
- Pipework
- Controls
- Installation complexity
For homeowners, see our Air Source Heat Pump Cost UK guide.
For non-domestic projects, use our Commercial Heat Pump Costs & Running Costs UK guide.
How to Compare R290 Heat Pumps
Once R290 has been identified as a suitable refrigerant option, compare the actual heat pumps rather than assuming all propane systems perform alike.
| Comparison Factor | What to Check |
|---|---|
| Output | Heating capacity at your actual outdoor and flow temperatures |
| Efficiency | COP and seasonal data at comparable conditions |
| Flow temperature | Performance at the temperature your system actually requires |
| Minimum modulation | How low the heat pump can reduce its output during mild weather or low demand |
| Noise | Sound data and any low-noise operating modes |
| Cold-weather operation | Available capacity and efficiency at winter design conditions |
| Safety requirements | Clearances and equipment-positioning requirements for the R290 charge |
| Controls | Weather compensation, zoning and system integration |
| Support | Installation, commissioning, warranty and long-term technical support |
For commercial procurement, our Commercial Heat Pump Installation, Design & Procurement Guide provides the wider specification checklist.
Should You Choose R290 Over Another Refrigerant?
R290 is a strong refrigerant option for many modern heat pumps, particularly where very low refrigerant climate impact, monobloc architecture or higher water temperatures are priorities.
But the better question is not:
“Which refrigerant is best?”
It is:
“Which complete heat-pump system best meets the property’s heat demand at the required temperatures?”
An R290 system should still be rejected if the proposed equipment is badly sized, unsuitable for the site’s noise constraints, unable to modulate appropriately or incompatible with the heating system.
R290 is an important direction in heat-pump technology, but refrigerant should remain one part of a wider system comparison rather than becoming the sole reason to choose a particular heat pump.
R290 Heat Pump Research by Topic
| If You Are Researching… | Continue Here |
|---|---|
| Heat pumps for your home | Best Air Source Heat Pumps UK → |
| Domestic installation costs | Air Source Heat Pump Cost UK → |
| Commercial heat pumps | Commercial Heat Pumps UK → |
| Large air-to-water systems | Commercial Air Source Heat Pumps UK → |
| Commercial manufacturer selection | Commercial Heat Pump Manufacturers UK → |
| Commercial costs | Commercial Heat Pump Costs UK → |
| Commercial design and installation | Commercial Heat Pump Installation → |
| Industrial process heat | Industrial Heat Pumps UK → |
| Higher water temperatures | High-Temperature Heat Pumps UK → |
Frequently Asked Questions
What does R290 mean on a heat pump?
R290 is the refrigerant designation for propane. An R290 heat pump uses propane within its refrigeration circuit to transfer heat from the source into the heating system.
Is R290 the same as propane?
Yes. R290 is propane used as a refrigerant. Refrigerant-grade R290 is used within equipment designed specifically for that refrigerant.
Is R290 an F-gas?
No. Propane is a hydrocarbon rather than a fluorinated greenhouse gas and is not part of the HFC quota system.
Is R290 refrigerant flammable?
Yes. R290 is highly flammable. Heat pumps using it are designed around this characteristic, and the model-specific installation requirements, safety clearances and applicable standards need to be followed.
Is an R290 heat pump safe for a home?
R290 can be used in domestic heat pumps designed for propane when the system is correctly located and installed. Many air-to-water applications use a monobloc design that keeps the sealed refrigerant circuit outdoors.
Is R290 better than R32?
R290 has a much lower direct climate impact and is not an HFC, but that does not make every R290 heat pump better than every R32 system. Compare complete system efficiency, output, noise, operating temperatures, modulation, safety requirements and support.
Are R290 heat pumps more efficient?
Not automatically. Refrigerant affects heat-pump design and performance, but actual efficiency depends on the complete system and operating conditions. Compare performance at equivalent outdoor and water temperatures.
Can R290 heat pumps produce high-temperature water?
Yes, R290 is used in heat pumps designed for relatively high heating-water temperatures. Maximum temperature varies by equipment, and efficiency at the required temperature should be checked rather than comparing maximum temperature alone.
Can an R290 heat pump get the £7,500 Boiler Upgrade Scheme grant?
An eligible R290 air-to-water heat pump can potentially qualify for the £7,500 BUS grant if the property, product, installer and installation meet current scheme requirements. There is no separate grant specifically for R290 refrigerant.
Sources & Further Reading
Heat Pump Guide UK uses authoritative UK sources wherever practical. Refrigerant regulation and product standards can change, so current requirements should be confirmed when a system is designed or installed.
- GOV.UK – Fluorinated Gases Guidance
- GOV.UK – F-Gas Restrictions for New Equipment
- GOV.UK – Great Britain HFC Phase-Down Reform
- DEFRA – F-Gas Regulation in Great Britain Assessment
- DESNZ – Air-to-Air Heat Pumps Literature Review
- HSE – Dangerous Substances and Explosive Atmospheres
- Ofgem – Boiler Upgrade Scheme
Commercial Heat Pump Guides
Considering an R290 Heat Pump?
Treat propane as one part of the specification. Compare the complete system at the temperatures, heat demand and operating conditions relevant to your property.