Quick and to the point, because I know you’re here for an answer and not for a sales brochure.
An R290 propane heat pump is a heat pump that uses propane (refrigerant R290) instead of a synthetic F-gas like R32 or R410A.
Propane is a natural refrigerant with the lowest GWP of the bunch (GWP 3). It reaches higher flow temperatures (up to roughly 70 to 75°C), so you can often keep your existing radiators. And it’s future-proof, because the European F-gas rules are banning the synthetic refrigerants step by step.
So is it the better choice? For the vast majority of homes: yes. But propane is flammable, and that comes with siting rules. I’ll tell you those honestly, including the metres.
Let me walk you through it calmly.
What is R290?
R290 is the official refrigerant name for propane. Yes, the same stuff as in your camping gas bottle, only in a tiny, sealed circuit inside the heat pump.
A refrigerant is the fluid that circulates inside a heat pump. Outside it absorbs heat (even in freezing weather), gets compressed, and releases that heat indoors to your heating water. No refrigerant, no heat pump.
For years we used synthetic gases for this: first R410A, later R32. Works fine, but they’re F-gases (fluorinated greenhouse gases) with a hefty climate impact if they leak.
R290 is a natural refrigerant. No fluorine, no chlorine, just a hydrocarbon that nature makes on its own.
And thermodynamically it’s simply a strong performer. On some points even better than the synthetic refrigerants. I’ll get to that in a moment.
What does GWP mean and why is R290’s so low?
GWP stands for Global Warming Potential. It tells you how much a kilo of a gas contributes to warming compared with a kilo of CO2 over 100 years. CO2 itself has GWP 1 by definition.
The lower the GWP, the less damage if the refrigerant leaks. And refrigerants do leak sometimes, during installation, from a fault, or at the end of their life.
Just look at the difference.
| Refrigerant | Type | GWP | Max flow temp (indicative) | F-gas status |
|---|---|---|---|---|
| R410A | Synthetic (F-gas) | ~2088 | ~55°C | Being phased out |
| R32 | Synthetic (F-gas) | ~675 | ~60-65°C | Banned in new monoblocks from 2027 |
| R290 (propane) | Natural | 3 | ~70-75°C | Stays allowed, future-proof |
Let that sink in for a second. R410A has a GWP of around 2088. So one kilo of leakage equals roughly two thousand kilos of CO2.
R290 sits at 3. You read that right: three.
That’s not a marketing trick, that’s a factor of seven hundred between R290 and R410A. And that’s exactly why Europe is tightening the screws.
Why are manufacturers switching to propane?
Short answer: because they have to, and because they can.
The “have to” comes from the revised F-gas Regulation (EU 2024/573). This law squeezes the availability of synthetic refrigerants step by step through what’s called a phase-down: less quota every year, so less F-gas on the market, so it gets pricier and scarcer.
The “can” comes from the fact that propane is simply an excellent refrigerant technically. Manufacturers didn’t have to give up performance, quite the opposite.
So instead of clinging to a refrigerant that’s being phased out, the big brands are now switching to R290 en masse. Bosch has announced a broad line-up of R290 models for 2026, and Vaillant, Daikin, Panasonic, Mitsubishi and LG all have propane models on the shelf.
When half an industry moves in the same direction, it’s usually not a fad.
The F-gas timeline: which years should you remember?
This is exactly the part where most articles stay vague. I’ll just lay the years out for you.
The regulation works with ban dates per system type and capacity class. The core of it.
| Year | What changes |
|---|---|
| 2025-2026 | Phase-down continues: less F-gas quota, R32 gets scarcer and pricier |
| 2027 | Ban on F-gases with a GWP above 150 in new monoblock heat pumps and air conditioners up to 12 kW. R32 (GWP 675) falls under this and is no longer allowed there |
| 2032 | Ban on all F-gases in new monoblock systems up to 12 kW |
| 2035 | Ban on all F-gases (including R32 and R410A) in new split air conditioners and split heat pumps |
Two things you need to know before you panic.
One: this is about new devices coming onto the market. If you have an R32 heat pump now, it can simply keep running. There are no end dates for servicing and topping up existing systems with a GWP below 2500, so your R32 pump does not become illegal.
Two: monoblock goes first (2027/2032), split later (2035). That’s logical, because propane almost always comes in a monoblock design. Why, I’ll explain shortly.
My level-headed reading: if you still buy a new R32 monoblock now, you’re deliberately buying into the category on its way out. You can, but I wouldn’t.
What is a monoblock and why is R290 nearly always in one?
Quick bit of jargon, because this matters for safety.
A monoblock heat pump has the complete refrigerant circuit in a single unit outside. Only heating water comes indoors, through two water pipes. So the propane never enters your home.
A split system has the refrigerant split across an outdoor part and an indoor part, with refrigerant lines running through the facade. With that setup the refrigerant does run into your home.
And that’s exactly why propane is nearly always monoblock. Propane is flammable, so you want to keep it outside and not run it through your living room.
Added bonus: with a monoblock the installer doesn’t have to couple any refrigerant lines. The circuit arrives sealed and filled from the factory. Less leak risk, less hassle.
Why does R290 reach higher flow temperatures?
For a renovation this is the most important selling point, and at the same time the point competitors explain worst.
The flow temperature is the temperature of the heating water the heat pump produces. The higher it is, the warmer your radiators can get.
Propane has favourable thermodynamic properties, so it can comfortably make water up to about 70 to 75°C, some models even higher, and it does so without efficiency collapsing. A classic R32 monoblock, in practice, often gets stuck around 60 to 65°C.
Why that difference can save you thousands.
In an old house with existing radiators this is crucial. Those radiators are designed for heating water of 70 degrees or more. If your heat pump can hit that, you don’t have to replace all those radiators with expensive low-temperature panels or underfloor heating.
In short, with an R290 pump the odds are much better that your existing heating simply keeps working. That saves a renovation.
A bit of honesty: efficiency is always highest at a low flow temperature. Run at 70 degrees all winter and you’ll use more than someone with underfloor heating at 35 degrees. But the “70 degrees on propane” option at least exists, and that’s exactly what a renovation home needs.
Is R290 safe? An honest take on flammability
Yes, provided it’s installed well. But I’m not going to tell you there’s nothing to it, because propane is flammable, plain and simple.
R290 falls into safety group A3. The A stands for low toxicity (not poisonous), the 3 stands for high flammability. Compare it to the gas bottle at your barbecue: not scary if you act sensibly, but definitely something to take seriously.
Why it’s manageable in practice.
The amount of propane in a heat pump is small, often a few hundred grams up to around a kilo, in a sealed circuit that arrives from the factory. Modern units have built-in safety: gas leak sensors, sealed switch boxes and safety valves.
And because it’s monoblock, that propane sits outside. If something ever leaks, it evaporates into the outside air instead of into your meter cupboard.
The real point of attention isn’t in the unit, but in the siting. And that brings me to the metres.
Outdoor unit safety distances: the metres you need to know
Propane is heavier than air. If gas leaks, it sinks to the ground and creeps to the lowest point. Think of a basement window, a vent low in the wall, a light well or a drain.
That’s why, with the safety zone, you don’t think of a flat circle on the ground but of a three-dimensional volume around the unit. Escaping gas can move down and sideways.
The practical rules installers work with (based on standard BS EN/IEC 60335-2-40).
- At least 1 metre of horizontal clearance to openings where gas can get inside: openable windows, doors, vents, basement shafts, light wells.
- No ignition sources in the safety zone: no outdoor socket, no switch, no open flame, no boiler flue nearby.
- For ignition sources a larger distance is often kept, towards 3 metres, or extra measures are taken.
- Special attention to anything lower than the unit, because that’s where leaking propane collects.
The exact distances differ per model and manufacturer, so always check the installation manual for your specific pump. But the thread running through it is clear: keep openings and sparks away from the bottom of the unit.
One more that’s often forgotten: an installer working with propane must hold a competence certificate for category A3 (flammable refrigerants). Feel free to ask about it. A good tradesperson shows it without grumbling.
Efficiency (SCOP): is propane more economical?
SCOP stands for Seasonal Coefficient of Performance, the efficiency measured across a whole heating season. A SCOP of 4.5 means: from 1 kWh of electricity you get 4.5 kWh of heat. The higher, the more economical.
R290 pumps score well across the board. A few examples from the market:
- Panasonic Aquarea L series: SCOP around 5.06.
- Vaillant aroTHERM plus: SCOP of about 4.65 at 35°C flow.
- Various R290 models sit in the range 4.5 to well over 5, depending on capacity and flow temperature.
Important to understand: SCOP is measured at a low flow temperature. Run at 70 degrees for your old radiators and the real-world efficiency will be lower. That goes for every heat pump, propane or not.
Propane really shines in the combination: high efficiency at low temperature, plus the ability to go high when needed, and on top of that it performs well in severe frost (-20 to -25°C).
What does an R290 heat pump cost?
Honestly: a bit more than a comparable R32 pump, but the difference is limited and the gap is shrinking.
I won’t name a hard price I can’t back up, I think that’s nonsense. I will give the order of magnitude, and I’ll label it as indicative.
- An R290 monoblock is often a little higher in unit price than R32, because there’s extra safety technology inside. Reckon on a premium in the hundreds of pounds, not the thousands.
- Government grants bring the purchase price down considerably. In the UK the Boiler Upgrade Scheme offers a fixed grant towards an air source heat pump, and amounts and schemes change, so check the current figure with the relevant authority.
- Because an R290 pump lets you keep your existing radiators more often, you save on the usually much bigger item: replacing your entire heat emitter system.
That last one is where the real money is. A few hundred pounds premium on the unit is nothing compared with the renovation of your heating that you avoid.
How much noise does an R290 heat pump make?
Comparable to other modern monoblocks, so usually no problem, provided it’s sited well.
The aroTHERM plus, for example, sits around 44 dB(A). Some units reach values towards 28 dB(A) at a few metres’ distance. In a consumer test a Bosch R290 model came out as one of the quietest.
Nuance: the safety distances for propane and the legal noise limits sometimes work against each other. You want the unit away from openings and away from the neighbour’s bedroom. Have a good installer look at that before you pour the foundation.
Which brands and models use R290?
Just about all the major players now have propane models. An overview of well-known R290 heat pumps on the market.
| Brand | Model (example) | Refrigerant | Max flow temp (indicative) |
|---|---|---|---|
| Bosch | Compress 3800i AW / Compress 7400i | R290 | ~75°C |
| Vaillant | aroTHERM plus | R290 | ~75°C |
| Panasonic | Aquarea L series | R290 | ~75°C |
| Daikin | Altherma 4 H | R290 | ~70°C+ |
| Mitsubishi | Ecodan R290 | R290 | ~70°C |
| LG | Therma V R290 | R290 | ~75°C |
| SPRSUN | R290 series | R290 | ~75°C+ |
The exact specs differ per capacity class and year of manufacture, so use this as a starting point and check the current datasheet. But the message is clear: propane is no longer a niche, it’s the new standard.
When is R290 the right choice?
Let’s get practical, because that’s what it’s about.
Choose R290 if:
- you have an existing home with normal radiators you’d rather not replace all of (the high flow temperature saves you here).
- you want a future-proof investment that doesn’t fall into the F-gas category on its way out.
- you have outdoor space where you can meet the safety distances to windows, doors and vents.
- environmental impact counts for you (GWP 3 versus 675 or 2088 is quite a difference).
Hesitate or look further if:
- you have a tiny spot where you really can’t keep the safety zone clear of openings and ignition sources. Then siting becomes a puzzle.
- you already have underfloor heating and run at low temperature: then the temperature advantage is less decisive, though the low GWP and future-proofing still argue for propane.
My level-headed verdict: for the average renovation home, an R290 monoblock in 2026 is simply the logical choice. Better temperature, lowest GWP, and you’re not buying something that vanishes from the shelves in a few years.
Frequently asked questions about R290 propane heat pumps
Is an R290 heat pump dangerous in my garden?
No, provided it’s correctly sited by a certified installer. The propane sits in a small, sealed circuit outside and the amount is limited. It comes down to the siting: keep the safety distances to windows, doors, vents and ignition sources.
Can an R290 heat pump drive my old radiators?
Often yes. Propane reaches flow temperatures up to about 70 to 75°C, which is enough for most existing radiators. That often stops you from having to replace your whole heat emitter system. Do have a heat loss calculation done to be sure.
Will my current R32 heat pump be banned soon?
No. The F-gas rules ban the sale of new devices with certain refrigerants, not the use of what you already have. Your existing R32 pump can keep running and can be serviced and topped up.
Why is R290 nearly always monoblock and not split?
Because propane is flammable and you’d rather keep it outside. With a monoblock the complete refrigerant circuit stays in the outdoor unit and only heating water comes into your home. With a split the propane would run through your home, and you don’t want that.
Is R290 more economical than R32?
In practice very comparable to slightly better, with SCOP values often between 4.5 and above 5. The real advantage of propane lies in the combination of good efficiency and high flow temperature, plus the much lower GWP.
Do I need a special installer for R290?
Yes. Anyone working with flammable refrigerants needs a category A3 competence certificate. Feel free to ask about it before you place the order.
To wrap up
R290 isn’t hype, it’s simply the logical next step: a natural refrigerant with a GWP of 3, high flow temperatures for your existing radiators, and a place in the future-proof category of the F-gas rules. The flammability calls for tidy siting, nothing more.
Want to really know where the money is leaking away in your house and how to bring your energy bill down by going greener? Come and have a look. I’ve laid it all out in my guide: energy-crusher.fredsdiyplans.com. No sales pitches, just level-headed steps that work.
Cheers from Fred Schouten
PS: Planning to install an R290 pump? First measure the distance to every window, every door and every vent with a tape measure. Five minutes of work that saves you a lot of hassle with the installer.