Which Ecodan size fits your home, how efficient and loud the R290 units are on their UK datasheets, how the grant works in each nation and why your installer's status sets a 3, 5 or 7-year warranty.
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A Mitsubishi heat pump for a UK house is an Ecodan, and the current one is the Ecodan R290: a monobloc outdoor unit in 5, 6, 8.5, 10 or 12 kW that runs on propane and heats water to as much as 75 °C. In the MCS product directory the 8.5 kW model (PUZ-WZ85VAA) has a SCOP of 4.47 at a 35 °C flow temperature and 3.51 at 55 °C.
Mitsubishi Electric sells Ecodan in the UK through its Living Environment Systems division in Hatfield, Hertfordshire, and says the R290 units are made at its factory in Livingston, Scotland. You buy one through an installer, and that installer's status in Mitsubishi Electric's partner programme sets how long your warranty runs: three, five or seven years on the heat pump. Ecodan suits you best if an installer near you holds one of the higher tiers and your home can be heated at a moderate flow temperature.
What we like
What we like less
Sorted by overall score, highest first.
How to read the ranking Scores out of 5. Quality: efficiency at 55 °C, outdoor sound power and maximum flow temperature of the model listed in our heat pump comparison. Warranty: 3.5 is the usual two-year manufacturer warranty; longer cover at no extra charge scores more, unclear terms or no cover at no extra charge score less. Price: our editorial price tier for the brand in the UK (5 = most affordable), an estimate rather than a price list. Overall: quality 50%, warranty 25%, price 25%. The full method is on our editorial method page.
Compare the specifications and warranties of the exact model.
Heat pump · 4 Versions
| Specifications | Ecodan R290 PUZ-WZ80VAA (8 kW monobloc, single phase) | Ecodan R290 PUZ-WZ85VAA (8.5 kW monobloc, single phase) | Ecodan R290 PUZ-WZ100VAA (10 kW monobloc, single phase) | Ecodan R290 PUZ-WZ120VAA (12 kW monobloc, single phase) |
|---|---|---|---|---|
| Output and type | ||||
| Heat output at A-7/W35 | 8.2 kW | 8.5 kW | 10 kW | 11.5 kW |
| Maximum flow temperature | 75 °C | |||
| Type | Monobloc | |||
| Power supply | 220-240 V 1~ 50 Hz | |||
| Efficiency on the EU label | ||||
| Energy class at 35 °C | A+++ | |||
| Energy class at 55 °C | A++ | |||
| Seasonal efficiency ηs at 35 °C | 176 % | 183 % | 189 % | 192 % |
| Seasonal efficiency ηs at 55 °C | 140 % | 143 % | 141 % | 142 % |
| Noise | ||||
| Outdoor sound power | 58 dB(A) | 54 dB(A) | 55 dB(A) | 55 dB(A) |
| Refrigerant | ||||
| Refrigerant | R290 | |||
| Refrigerant charge | 1 kg | 0.6 kg | 0.82 kg | 0.82 kg |
| Dimensions and weight | ||||
| Dimensions (H × W × D) | 1,020 × 1,050 × 480 mm | 1,040 × 1,050 × 480 mm | 1,040 × 1,050 × 480 mm | 1,040 × 1,050 × 480 mm |
| Weight | 117 kg | 103 kg | 120 kg | 120 kg |
Ecodan is Mitsubishi Electric's air-to-water range: heat pumps that heat radiators or underfloor heating and a hot-water cylinder. The current outdoor units are the Ecodan R290:
| Model | Output at −7 °C | Supply | Size (H × W × D) | Weight |
|---|---|---|---|---|
| PUZ-WZ50VAA | 5.2 kW | single phase | 1,020 × 1,050 × 480 mm | 89 kg |
| PUZ-WZ60VAA | 6.2 kW | single phase | 1,020 × 1,050 × 480 mm | 89 kg |
| PUZ-WZ85VAA / YAA | 8.5 kW | single / three phase | 1,040 × 1,050 × 480 mm | 103 / 117 kg |
| PUZ-WZ100VAA / YAA | 10.0 kW | single / three phase | 1,040 × 1,050 × 480 mm | 120 / 131 kg |
| PUZ-WZ120VAA / YAA | 11.5 kW | single / three phase | 1,040 × 1,050 × 480 mm | 120 / 131 kg |
Output is the datasheet figure at −7 °C outside and a 35 °C flow (A-7/W35), so the 12 kW model shows 11.5 kW. On the UK datasheets every size reaches a 75 °C water outlet temperature and runs from −25 °C to 46 °C outside. VAA is single phase, YAA three phase.
In a monobloc the refrigerant circuit stays sealed in the outdoor unit and only water pipes cross the wall; in a split, refrigerant pipes run to an indoor unit and are connected on site.
R290 is propane, with a global warming potential of 3 under the GB F-gas rules, against 675 for R32. Because propane is flammable, the outdoor unit needs a protective zone around its base: for the 5 and 6 kW units and the older 8 kW PUZ-WZ80VAA, Mitsubishi Electric's service manual sets 1 m around the unit and 0.3 m up from the ground in the open, more in corners. Since January 2026 Mitsubishi Electric's installation manual restricts only building openings and basement entrances in that zone, such as windows, doors and vents; drains and downpipes are allowed. Ask your installer for the zone of your exact model.
Indoors, Mitsubishi Electric pairs the outdoor unit with its own pre-plumbed cylinders; the datasheet rates hot-water efficiency with the EHPT20X-MEHEW cylinder.
SCOP, the seasonal coefficient of performance, is the heat delivered over a heating season for each unit of electricity, on a standard test. The MCS product directory lists it for each flow temperature, and the UK datasheets print the same values. Under the MCS design standard MIS 3005-D, your installer gives you the expected SCOP of your design in writing before installation.
| Model | MCS SCOP 35 °C | MCS SCOP 45 °C | MCS SCOP 55 °C | Sound power | Sound at 1 mSound pressure level 1 m from the unit at 7 °C outside and 55 °C water |
|---|---|---|---|---|---|
| PUZ-WZ50VAA | 4.42 | 3.90 | 3.38 | 56 dB(A) | 40 dB(A) |
| PUZ-WZ60VAA | 4.39 | 3.90 | 3.43 | 56 dB(A) | 40 dB(A) |
| PUZ-WZ85VAA | 4.47 | 3.96 | 3.51 | 54 dB(A) | 40 dB(A) |
| PUZ-WZ100VAA | 4.62 | 4.01 | 3.48 | 55 dB(A) | 40 dB(A) |
| PUZ-WZ120VAA | 4.71 | 4.08 | 3.51 | 55 dB(A) | 40 dB(A) |
MCS SCOP
| Model | 35 °C flow | 45 °C flow | 55 °C flow |
|---|---|---|---|
| 5 kW | 4.42 | 3.90 | 3.38 |
| 6 kW | 4.39 | 3.90 | 3.43 |
| 8.5 kW | 4.47 | 3.96 | 3.51 |
| 10 kW | 4.62 | 4.01 | 3.48 |
| 12 kW | 4.71 | 4.08 | 3.51 |
The gap between the columns matters more than the gap between sizes. For the 8.5 kW model, 4.47 ÷ 3.51 = 1.27: on the test, the same heat at a 55 °C flow takes about 27% more electricity than at 35 °C. Your radiators set the flow temperature, so the design does more for your bills than the choice of size; the 75 °C is headroom, not a target.
Measured in real homes, results are lower: the government-funded Electrification of Heat trial measured a median SCOP of 2.78 across 428 air source heat pumps. At about that level, our example home (a 1970s gas semi using 9,500 kWh of gas a year, 85% boiler efficiency assumed) would pay about the same for its heating units with a heat pump as with its boiler, on Ofgem price cap unit rates (GB average, direct debit, 1 October to 31 December 2026, no VAT on electricity in Great Britain until 31 March 2027) with standing charges left out; the result depends on the house, the installation and the tariff. The arithmetic is in heat pump running costs.
Sound power, 54 to 56 dB(A) to BS EN 12102 on the UK datasheets, is a property of the unit; compare models on it. Sound pressure, 40 dB(A) at 1 m with 7 °C outside and 55 °C water, is what you hear at that distance, and it falls as you move away.
In England and Wales, permitted development needs the MCS 020(a) calculation to show 37.0 dB(A) or less at 1 m outside the nearest window or door of a neighbour's habitable room. It uses sound power, never a low-noise-mode figure.
An example: the 8.5 kW model (54 dB(A)) on the ground against your house wall (two reflecting surfaces, factor 4), with no fence in the way. At 3 m from a neighbour's bedroom window, 54 + 10 × log(4 ÷ (4 × π × 3²)) = 54 − 14.5 = 39.5 dB(A), over the limit. At 5 m the same sum gives 35.0 dB(A), inside it; the break point is about 4 m. A solid fence at least 18 mm thick that hides the unit completely takes 10 dB off. Placement and the other planning conditions are in heat pump noise; check with your local planning authority before you commit to a spot.
All five Ecodan R290 sizes are in the MCS product directory, with certificates to August 2033 (5 and 6 kW) or February 2035 (8.5 to 12 kW). The Boiler Upgrade Scheme in England and Wales also needs a SCOP of at least 2.8. The Ecodan R290 clears that at 55 °C, but not at every flow temperature: the 5 kW unit lists 2.66 at 65 °C, so ask for the SCOP of your design in writing. Mitsubishi Electric's partner tiers change your warranty, not the grant.
In England and Wales, the Boiler Upgrade Scheme takes £7,500 off an air source heat pump if your home qualifies; some off-gas-grid homes replacing oil or LPG may qualify for £9,000 instead, for applications properly made from 21 July 2026 to 31 March 2027. Your installer, who must be MCS-certified and in an approved consumer code such as RECC or HIES, applies to Ofgem and deducts the grant from your bill, so get the voucher before work starts. A heat pump supplied and installed in your home also carries 0% VAT until 31 March 2027, then 5%. Scotland and Northern Ireland differ: Scotland has its own grant and loan through Home Energy Scotland, and Northern Ireland has no grant open to every homeowner; the details are in heat pump grants.
The homeowner warranty's length depends on the installer's status in Mitsubishi Electric's partner programme when your heat pump is commissioned (Mitsubishi Electric's documents call it a guarantee). Check the status on Mitsubishi Electric's installer finder or with the Ecodan Homeowner Helpline (0161 866 6064; Monday to Friday 8am to 5pm, Saturday 8am to noon).
| Installer's status | Heat pump | Cylinder and interface | Registered?Within 3 months of commissioning |
|---|---|---|---|
| Domestic Heating Solutions Partner | 7 years | 3 years | needed |
| Ecodan Accredited Installer | 5 years | 3 years | needed |
| Ecodan Standard Account Holder | 3 years | 3 years | needed |
| Any status, not registered in time | 12 months | 12 months | – |
It runs from commissioning and covers Ecodan heat pumps under 20 kW with Mitsubishi Electric's cylinders and interface equipment. The conditions:
Mitsubishi Electric's separate terms for installers say an installer's own enhanced warranty reverts to the standard term if it loses its status; the homeowner terms fix your warranty length at commissioning. Get the installer's tier and the warranty length in writing with the quote.
Ecodan works with Mitsubishi Electric's MELCloud Home app for Apple and Android: change settings from anywhere, set schedules for heating and hot water, see live temperatures and track energy use; it also links to Amazon Alexa.
Mitsubishi Electric's app pages name no tariff integration, but schedules let you heat the cylinder in the cheaper hours of a time-of-use tariff.
A gas semi with radiators. The 8.5 kW model sits close to the 8 kW median size of air source heat pumps whose Boiler Upgrade Scheme grants were paid from July to September 2026, and the 75 °C gives headroom if a few radiators are small. Efficiency is best when your radiators let the flow temperature stay at 55 °C or below; heat pump radiators explains how to get there.
A smaller or well-insulated home. The 5 and 6 kW units cover lower heat losses; the heat-loss survey decides the size.
A higher-tier installer nearby. With an Accredited Installer or a Domestic Heating Solutions Partner, the five or seven years come at no extra charge, provided you register and keep up the yearly servicing.
Less suited if your installer is a Standard Account holder and long cover matters to you, if you live in Northern Ireland, where the homeowner warranty doesn't apply, or if the outdoor unit has to stand close to a neighbour's window.
How Ecodan fares in our comparison. In our comparison of air source heat pumps we score the model nearest 8 kW from each brand on four published criteria: MCS SCOP at 55 °C (40%), outdoor sound power (25%), the warranty you get at no extra charge (25%) and maximum flow temperature (10%). For the PUZ-WZ85VAA, the 75 °C flow and the five- or seven-year warranty at no extra charge from a higher-tier installer, provided you register and service it yearly, raise the score; the MCS SCOP of 3.51 at 55 °C and 54 dB(A) sound power lower it. Manufacturers and installers don't pay for placement; how we score is in our editorial method.
How to put two quotes side by side, and what consumer-code protection to ask about, is in choosing an MCS installer.
Mitsubishi Electric says the Ecodan R290 is made at its factory in Livingston, Scotland. Its UK datasheets list the range's countries of origin as the United Kingdom, Italy, Turkey, Japan, Thailand and Malaysia, so ask your installer where a particular unit was built if that matters to you.
Three, five or seven years on the heat pump, depending on whether your installer is a Standard Account Holder, an Ecodan Accredited Installer or a Domestic Heating Solutions Partner when it commissions the system. Cylinders and interface equipment get three years. You must register within 3 months of commissioning or the warranty is limited to 12 months, and the system needs a service every 12 months.
Mitsubishi Electric doesn't publish homeowner prices; the installer prices the whole job. Across all brands, the median installed price of an air source heat pump in England and Wales, for jobs whose Boiler Upgrade Scheme grants were paid from July to September 2026, was £12,826 before the grant, as reported by MCS installers, with VAT included. In England and Wales, if your home qualifies, the £7,500 Boiler Upgrade Scheme grant comes off that.
The R290 outdoor units have a sound power of 54 to 56 dB(A) and a sound pressure of 40 dB(A) at 1 m, according to Mitsubishi Electric's UK datasheets. What a neighbour hears depends on distance, walls and fences: in our example the 8.5 kW model, on the ground against a wall with no fence, needs about 4 m from a neighbour's window to meet the 37 dB(A) test in England and Wales.
All five Ecodan R290 sizes are MCS-certified, which the Boiler Upgrade Scheme in England and Wales requires along with a SCOP of at least 2.8 and an MCS-certified installer. Whether your home qualifies for the £7,500 grant in England and Wales depends on the property, and the installer applies. Scotland and Northern Ireland have different schemes.
Both are monobloc outdoor units. The R290 range uses propane, reaches 75 °C and comes in 5 to 12 kW; the older R32 range uses a refrigerant with a far higher global warming potential (675, against 3 for propane under the GB F-gas rules). Mitsubishi Electric's current UK range page leads with the R290.
Reading time: 15 min
Heat pump noise explained: sound power and sound pressure, how distance, walls and fences change the level, the MCS 020(a) test for permitted development in England and Wales with a worked example on a UK datasheet, placement, what reduces noise and how to handle complaints.
Read moreHeat pump noise
Reading time: 14 min
Heat pump running costs in our example 1970s semi: 2,884 kWh and £759 a year at SCOP 2.8, £850 at 2.5 and £686 at 3.1 (Ofgem price cap, 1 October to 31 December 2026), against £865 for gas including a £108 standing charge that ends only if the gas supply is disconnected, as we assume.
Read moreHeat pump running costs
Reading time: 16 min
The Boiler Upgrade Scheme in full: amounts in England and Wales, the £9,000 for oil or LPG homes to 31 March 2027, who qualifies, the six steps from quote to voucher, Scotland and Northern Ireland, loans and 0% VAT to 31 March 2027.
Read moreHeat pump grants
Reading time: 15 min
Radiator output at heat-pump temperatures with Stelrad's ΔT factors, MCS room-by-room sizing, two rooms of our example semi worked through, flow temperature and England's 55 °C design rule, weather compensation, balancing and a checklist.
Read moreHeat pump radiators
Reading time: 15 min
Seven air source heat pumps around 8 kW ranked from MCS certificate data, UK warranty terms and makers' documents, with our weights, every model's values, a worked score, a noise example and a quote checklist.
Read moreBest air source heat pumps
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How to choose an MCS-certified heat pump installer: checking certification and consumer-code membership, what a complete quote and design must show, warning signs, deposit protection under RECC and HIES, and cancellation rights.
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