Mitsubishi Electric Ecodan R290 heat pumps: models, specifications and warranty

The Ecodan R290 is Mitsubishi Electric's high-temperature air source heat pump, sold in the UK in 5kW, 6kW, 8.5kW, 10kW and 12kW outputs, in single and three phase versions and in standard or coastal protection builds¹. It is a monobloc: one outdoor unit does the work, and it runs on R290, a hydrocarbon refrigerant with a global warming potential of 0.02².

The point of the design is retrofit. It reaches flow temperatures of up to 75°C, which is hot enough to serve the radiators and narrow microbore pipework already fitted in a great many UK homes, and it is stated to keep working down to an ambient temperature of -25°C². Mitsubishi Electric describes it as suited to larger homes and properties with higher heat loss, and to homes that cannot undergo extensive insulation work².

For a household, that means the fuel changes but the pipework often does not. The unit is manufactured at Mitsubishi Electric's factory in Livingston, Scotland⁴. What follows is what the range covers, what the published figures are, and where the dependence on the grid, the installer and the manufacturer's app remains.

What the Ecodan R290 is, and why microbore matters

A conventional air source heat pump works best when it can run cool, because a heat pump's efficiency rises as the water temperature it produces falls. That is why so many installations come with new, larger radiators. The Ecodan R290 takes the opposite route: it produces water hot enough to match a traditional gas boiler, so the existing emitters can often stay.

Mitsubishi Electric states the R290 models are fully compatible with existing microbore pipework, allowing homeowners to move to renewable heating without a full system replacement². In later material the company describes the R290 advance as offering a practical solution for retrofitting a home, enabling many homes to retain existing radiators and pipework, including microbore systems commonly found in UK housing stock⁵. In the SNG retrofit work it describes high-temperature Ecodan heat pumps as working effectively and efficiently with legacy microbore and small bore systems⁶.

That is the central claim, and it is a maker's claim about its own product. It matters because microbore, the narrow-bore pipework used in a large share of UK housing, has historically been the reason a household was told a heat pump was not viable without re-piping. The unit is a fully electric source of heating and hot water, so the gas connection goes and the electricity supply carries the whole load¹.

The trade-off is that running hotter costs efficiency. A heat pump producing 75°C water is working harder than one producing a lower flow temperature, and the published A+++ rating is measured at 35ºC, not at the top of the range¹. The design buys compatibility with the existing system; it does not make the physics disappear. More on how flow temperature and efficiency interact is at heat pump flow temperature, and the wider case for this class of unit is at high-temperature heat pumps.

The range: 5kW to 12kW, single and three phase

The range began smaller than it is now. Mitsubishi Electric states the Ecodan R290 was originally available in 5kW and 6kW, with the additional 8.5kW, 10kW and 12kW models added later². The full line-up is 5kW, 6kW, 8.5kW, 10kW and 12kW, available in single and three phase, and in standard and coastal protection versions¹.

The coastal protection option is worth noting for anyone near the sea, since salt air is hard on outdoor metalwork. Three phase matters for larger outputs, where a single phase supply may not carry the load comfortably alongside the rest of a house's demand. The company's own guidance on what a supply needs is at electricity supply for a heat pump.

The 8.5kW, 10kW and 12kW models are the ones Quiet Mark lists on its own site⁷. For context on how the outputs compare with other makers, the R290 versus R32 comparison sets out what changed in the refrigerant, and the Ecodan R32 monobloc page covers the model this range replaces.

Specifications: 75°C flow, -25°C operation, A+++ at 35ºC

The headline figures are consistent across the maker's own pages and the independent listings. Flow temperatures of up to 75°C appear on the product page, in the launch material and in the independent product listings for the 8.5kW, 10kW and 12kW units¹. The guaranteed operating range down to -25°C ambient appears in the same places².

The efficiency class is A+++ for heating at 35ºC, on a scale running from A+++ down to D¹. That is a rating at a specific test condition, not a promise about a particular house. Mitsubishi Electric states the unit can achieve Coefficient of Performance values greater than four in heating mode¹⁰. COP is a single-point measurement; a full year's performance in a real house is a different number, and the difference between the two is explained at heat pump efficiency: COP, SCOP and SPF.

The company also states the unit can reach a heating temperature of 75°C at -15°C ambient in heating mode, matching a traditional gas boiler¹⁰. That is the figure that matters most in a cold snap: it is one thing to reach 75°C on a mild day and another to hold it when the outdoor temperature is well below freezing.

R290 refrigerant: a global warming potential of 0.02

R290 is propane, a hydrocarbon refrigerant. Mitsubishi Electric states the Ecodan R290 uses R290 with a global warming potential of only 0.02¹. That is the number that separates this generation from the one before it.

The comparison that matters is with the R32 units the R290 range replaces. Mitsubishi Electric has announced a transition from Ecodan R32 to the extended Ecodan R290 range, and in January 2026 reminded installers that the R32 phase-out had one year remaining before withdrawal, encouraging a full move to R290³. The refrigerant rules behind that shift, and what they mean for servicing and future supply, are set out at heat pump refrigerants: R290, R32 and the F-Gas rules.

R290's low global warming potential is not unique to this brand. Grant states its Aerona 290 uses R290 with a low global warming potential of 3, and LG lists its Therma V R290 monobloc at GWP 3¹¹. The figures published by different makers for the same refrigerant vary, which is a reminder that these are stated values rather than a single agreed number. What is consistent is the direction: R290 sits far below the fluorinated refrigerants it replaces.

There is a practical consequence. R290 is flammable, which is why the installation rules around it are stricter than for R32, why installer training covers safe handling, and why the siting rules described below exist at all. The benefit to a household is a lower refrigerant charge with a far smaller global warming impact if it ever leaks.

Noise, dimensions and weight before choosing a position

Weight is the first practical constraint. Quiet Mark lists the 8.5kW unit at 103kg, and the 10kW and 12kW units at 120kg each⁷. That is a substantial lump to lift onto a wall bracket, and it shapes both the mounting and the number of people needed on site.

On noise, the published figures are not all on the same basis. Mitsubishi Electric describes the Ecodan R290 as designed to operate quietly¹⁰, and one case study reports an installation running at a noise level of just 56dB(A)⁴. A separate company article gives 40dBA at one metre away¹³. Those two numbers are far apart: one is a measured installation and the other a figure quoted at a stated distance, and neither states the same conditions. Both are given here as published.

The Ecodan R290 carries Quiet Mark accreditation from the Noise Abatement Society, and Mitsubishi Electric states the unit is manufactured in the UK with that accreditation². Quiet Mark lists the 8.5kW, 10kW and 12kW models individually⁷. Quiet Mark's own round-up of the quietest heat pumps on the market places the range in that group¹⁴.

Certification is a label, not a measurement of your garden. What a neighbour actually hears depends on distance, on whether the unit faces a wall or an open boundary, and on whether it is running hard in cold weather. The assessment method that governs planning in England is explained at MCS 020: the heat pump noise assessment, and the general picture is at how noisy is a heat pump.

Retrofit compatibility: radiators, pipework and cylinders

The retrofit case rests on three things staying put: the radiators, the pipework and, often, the hot water cylinder.

On radiators and pipework, Mitsubishi Electric states the R290 models can retain existing radiators and pipework, including microbore systems commonly found in UK housing stock⁵, and that they are fully compatible with existing microbore pipework². In the SNG work the company describes the high-temperature units as working effectively and efficiently with legacy microbore and small bore systems⁶. Whether a specific house's radiators are adequate is a heat loss question, not a brand question, and it is covered at do I need to upgrade my radiators for a heat pump.

On cylinders, the Ecodan R290 pairs with the FTC7 packaged cylinder range, which Mitsubishi Electric describes as designed to integrate with Ecodan monobloc air source heat pumps, and which is available in packaged, pre-plumbed slimline and pre-plumbed standard forms¹. The packaged cylinder is described as offering flexible product placement¹⁵. Cylinder sizing and coil choice are covered at hot water cylinders for heat pumps.

On time, Mitsubishi Electric states Ecodan heating systems are typically installed in less than two days¹⁶. In the SNG retrofit installations the company describes heat pump system installation as taking as little as two days, around 40% quicker⁶. That is the maker's figure for its own installations, and it assumes a like-for-like swap rather than a change of system type.

One worked example gives a sense of scale. A three bedroom terraced house built in 1996, fitted with a 5kW Ecodan, a high pressure cylinder and new radiators, with installation and commissioning, came to £6,397 in total¹⁷. That is a single documented installation, not a price list, and it includes new radiators, so it is not a like-for-like comparison with a swap that keeps the existing emitters. Prices for a specific home are installer-quoted.

Protection zones and siting: what changed in January 2026

R290 is flammable, so the unit has a protection zone around it, and what may sit inside that zone has historically constrained where it can go. In January 2026 Mitsubishi Electric increased the flexibility of those zones following a technical and safety review, and amended the Ecodan R290 installation manual to reflect it³.

The change lifted restrictions on several features. Grooves, waste-water systems, inlets in sewers and waste-water shafts, and downpipes are now explicitly permitted within the protection zone³. That is a meaningful widening for the tight side returns and rear elevations where many UK homes would otherwise have nowhere to put an outdoor unit.

What remains is narrower than before. Restrictions now apply only to building openings or entrances to basements, such as windows, doors and ventilation openings, within 300mm from the base³. So the constraint is about where air can enter a building, not about every object near the unit.

The wider question of where an outdoor unit can go, including permitted development rights, is covered at where a heat pump outdoor unit can go, with the nation-by-nation position at heat pump planning permission in England, Scotland, Wales and Northern Ireland. The Energy Saving Trust has responded to consultation on permitted development rights, including a proposal to raise the maximum height of electric upstands for EV recharging from 2.3 metres to 2.7 metres where installed outside the curtilage of a dwellinghouse or block of flats¹⁸.

Installer training and what it means for your quote

R290 work is not covered by an ordinary gas qualification. Mitsubishi Electric runs an R290 installer course covering R290 system fundamentals, mechanical and electrical installation, commissioning procedures, servicing and fault finding, and safe transportation, handling and maintenance³. It is delivered through a blended online and hands-on approach, through the company's online learning platform and at its training centres³.

That matters when comparing quotes. Two installers may both be competent and only one may hold the R290 training, and the difference shows up in how confidently the protection zone, the refrigerant handling and the commissioning are dealt with. The company has also launched a scheme with Alto Energy that lets gas boiler installers deliver Ecodan heat pump installations with MCS compliance, commissioning, certification and grant paperwork handled by Alto Energy⁵. The general certification picture is at heat pump standards and certification.

There is also a safety notice to be aware of. Electrical Safety First lists a Mitsubishi Electric heat pump Ecodan product recall on its site¹². Anyone buying or owning an Ecodan should check the model and serial number against that notice rather than assume it does not apply.

On the electrical side, a heat pump adds a significant continuous load, and the consumer unit may need attention. Surge protective devices are one consideration: guidance notes that if enough space is not available in the consumer unit, a device could be installed in an external enclosure adjacent to the existing consumer unit¹³. Who pays for any supply upgrade is covered at who pays if my electricity supply needs upgrading for a heat pump.

MELCloud, controls and what owning one means for independence

The Ecodan R290 is MELCloud enabled, with remote control, monitoring, maintenance and technical support¹. The FTC7 packaged cylinder is likewise described as MELCloud enabled¹⁵. In practice that means an app on a phone, a connection to Mitsubishi Electric's servers, and a set of functions that only work while both are available.

That is the clearest dependence the product creates, and it is worth being plain about it. Local control at the unit and at the cylinder continues without an internet connection. Remote scheduling, monitoring and remote diagnostics do not. A household that wants the heat pump to run regardless of what happens to a broadband line or a manufacturer's cloud service should understand which functions sit on which side of that line. The wider picture is at heat pump controls, weather compensation and smart operation.

The other dependencies are the ones any heat pump brings. The unit runs on electricity, so the home stays connected to the grid and to an electricity supplier, and the running cost depends on the tariff and on the spark gap between electricity and gas prices, which Mitsubishi Electric itself has called on policymakers to address⁵. The unit is made in Scotland, which shortens the supply chain for parts and service, but the company is Japanese-owned and the controls and app are its own⁴.

What changes is the fuel. A gas boiler keeps a home on the gas grid and on a gas supplier; the Ecodan R290 removes both, at the cost of a larger electricity demand and a dependence on the manufacturer's app for the remote functions. The full picture of what that trade means is at heat pumps and household energy independence, and the cost side is at how much does a heat pump cost in the UK.