Quick answer: The Grant Aerona 290 is a quiet, efficient monobloc air source heat pump that comes in five sizes from 4kW to 15.5kW, runs on low-impact R290 refrigerant, reaches flow temperatures of up to 75°C and carries a 7-year guarantee when fitted by a Grant G1 installer. It is a particularly good fit for rural and oil-heated homes, and a typical installed system costs roughly £8,000 to £18,000 before Home Energy Scotland funding, depending on the size of your home.
A quick note before we start, because this one trips a lot of people up. If you searched for “grant heat pump”, you might be looking for one of two very different things: heat pumps made by the manufacturer Grant UK, or grant funding to help pay for a heat pump. This review is about the first one, Grant UK’s Aerona range. If it’s money you’re after, our guide to the Home Energy Scotland grant and loan explains what’s available and how to apply. You’ll also find a short funding section further down this page.
I survey and fit heat pumps across Edinburgh, the Lothians and Fife, so you’ll get Grant UK’s own specs alongside my honest take on where the Aerona works well and where it doesn’t.
Grant Heat Pump Review: At a Glance
Grant UK is a long-established heating manufacturer best known for its oil boilers, and the Aerona 290 is its fifth generation of air source heat pump. Here are the key facts in one place.
| Feature | Grant Aerona 290 |
|---|---|
| Manufacturer | Grant Engineering (UK) Ltd, part of the Grant business founded in 1978 |
| Type | Monobloc air-to-water heat pump |
| Sizes | 4kW, 6.5kW, 9kW, 12kW and 15.5kW |
| Refrigerant | R290 (propane), Global Warming Potential of 3 |
| Max flow temperature | 75°C for heating, 70°C for hot water |
| SCOP (35°C flow) | 4.56 to 5.08 depending on size |
| SCOP (55°C flow) | 3.33 to 3.74 depending on size |
| Energy rating | A+++ at 35°C, A++ at 55°C |
| Operating range (heating) | Outdoor temperatures from -25°C to 35°C |
| Noise | Quiet Mark approved; 40 to 46 dB(A) sound pressure at 1 metre |
| Controls | Aerona Smart Controller with weather and load compensation, plus app access via Wi-Fi hub |
| Guarantee | 7 years when installed by a G1 installer (T&Cs apply, annual service required) |
| Power supply | Single phase, 230V |
Is a Grant Aerona Heat Pump Worth It?
For most homes we survey, yes. The Aerona 290 posts strong efficiency figures, is genuinely quiet, and its 75°C maximum flow temperature gives it more flexibility with existing radiators than older low-temperature units. Grant UK also has a long history with rural, off-gas homes, and that shows in how well the range suits properties coming off oil.
It isn’t right for everyone. R290 units must be sited carefully, the larger models are big, and as with any heat pump the result depends more on a proper heat loss survey than on the badge on the box.
Pros and Cons of Grant Aerona Heat Pumps
| Pros | Cons |
|---|---|
| High SCOPs: up to 5.08 at 35°C flow on the 6.5kW model | The 7-year guarantee depends on a G1 installer and annual servicing |
| Up to 75°C flow, so more existing radiators can often stay | R290 units need clear safety zones around them, which can limit where they go |
| Quiet Mark approved across the range | 12kW and 15.5kW units stand over 1.3 metres tall and weigh 153 to 180kg |
| Wide size range, including a 15.5kW single-phase unit for big, draughty homes | Running costs climb if the system has to run at high flow temperatures all winter |
| Rated to run in outdoor temperatures down to -25°C | Many of Grant UK’s online reviews are about its oil boilers, so there’s less heat pump-specific owner feedback |
| Low-GWP refrigerant and MCS accredited, so it works with Scottish funding | Glycol can’t be used, so frost protection relies on heaters and anti-freeze valves that must be fitted correctly |
How Efficient Are Grant Aerona Heat Pumps?
Very efficient on paper. Grant UK lists a seasonal coefficient of performance (SCOP) of between 4.56 and 5.08 at a 35°C flow temperature, and between 3.33 and 3.74 at 55°C, which earns every model an A+++ rating at 35°C and A++ at 55°C.
A SCOP of 4.7 means you get about 4.7 units of heat over a heating season for every unit of electricity you pay for. With electricity at around 26p per kWh under the Ofgem price cap for October to December 2026, that works out at roughly 5.5p per kWh of heat. At a SCOP of 3.7 it’s closer to 7p. For comparison, gas at around 8p per kWh burned in a 90% efficient boiler costs roughly 8.9p per kWh of heat.
The figures below come from Grant UK’s Aerona 290 product page and data sheet.
| Model | Output (7°C air / 35°C water) | SCOP at 35°C | SCOP at 55°C | Sound pressure at 1m | Weight (empty) |
|---|---|---|---|---|---|
| Aerona 290 4kW (HPR2904) | 4.09kW | 5.00 | 3.66 | 40 dB(A) | 99kg |
| Aerona 290 6.5kW (HPR29065) | 7.62kW | 5.08 | 3.62 | 44 dB(A) | 115kg |
| Aerona 290 9kW (HPR2909) | 9.38kW | 4.74 | 3.69 | 46 dB(A) | 131kg |
| Aerona 290 12kW (HPR29012) | 12.18kW | 4.74 | 3.74 | 44 dB(A) | 153kg |
| Aerona 290 15.5kW (HPR290155) | 16.16kW | 4.56 | 3.33 | 45 dB(A) | 180kg |
Note the gap between the 35°C and 55°C columns: the lower the flow temperature your home can run at, the cheaper your heating. If you’re unsure whether your current radiators are up to the job, our article on whether you need new radiators for a heat pump is a good place to start.
In one Grant UK case study, the installer of a 6.5kW Aerona 290 in a 1979 detached house reported a SCOP of 5.8 at a 45°C design flow temperature on the existing radiators. That’s a single manufacturer-published example, not an independent test. For a fuller picture of what to expect on your bills, see our guide to heat pump running costs in Scotland.
Grant Aerona Air Source Heat Pump Models
Grant UK currently sells two Aerona ranges: the Aerona 290, its fifth-generation heat pump using R290, and the previous-generation Aerona³ R32. Both appear in Grant UK’s August 2026 Aerona brochure, but the Aerona 290 is the one most homeowners will now be quoted.
| Model | Refrigerant | Sizes (kW) | Max flow temp | Notes |
|---|---|---|---|---|
| Grant Aerona 290 | R290 (GWP 3) | 4, 6.5, 9, 12, 15.5 | 75°C heating, 70°C hot water | Fifth generation. Monobloc, powder-coated black casing, Quiet Mark approved, rated down to -25°C. Uses the Aerona Smart Controller. First sizes orderable from October 2024, with the 12kW and 15.5kW following in early 2025. |
| Grant Aerona³ R32 (often sold with the Aerona Smart Controller kit) | R32 (GWP 675) | 6, 10, 13, 17 | 55°C heating set point (per Grant UK’s Aerona³ instructions) | Previous generation. SCOP of 4.54 to 5.40 at 35°C. Rated down to -20°C. Works with the Aerona Remote Controller or Smart Controller, with built-in weather compensation. |
The Aerona 290’s main advantages over the Aerona³ are its far lower-impact refrigerant, quieter operation (around 40 to 46 dB(A) at 1 metre against roughly 50 to 54 dB(A) for the Aerona³) and the much higher flow temperature, which matters a lot in older Scottish homes.
The Aerona Smart Controller has a 4.5-inch colour touchscreen, handles up to three heating zones plus hot water, combines weather and load compensation, and works by app or web portal with the Aerona Wi-Fi hub.
How Much Does a Grant Aerona Heat Pump Cost?
A fully installed Grant Aerona system typically costs between about £8,000 and £18,000 before funding, depending mainly on the size of heat pump your home needs and how much pipework, radiator and cylinder work is involved. These are our typical supply-and-fit ranges for air source heat pumps, including the unit, hot water cylinder, labour and commissioning.
| Property | Likely Aerona 290 size | Typical installed cost (before funding) |
|---|---|---|
| 1 to 2 bedroom flat or house | 4kW to 6.5kW | £8,000 to £11,000 |
| 3 to 4 bedroom house | 9kW to 12kW | £11,000 to £15,000 |
| 5+ bedrooms or larger rural home | 15.5kW | £15,000 to £18,000 |
Treat these as a guide only. Your price is fixed after a home survey and heat loss calculation, and our full heat pump cost guide breaks down what pushes a quote up or down. For a wider benchmark, Which? reports government figures showing the average installed cost of an air source heat pump (around 8.4kW) in England and Wales was £13,431 for October to December 2025.
The Grant Aerona range is MCS accredited, so it qualifies for Scottish funding:
- Home Energy Scotland grant: up to £7,500 towards an air-to-water heat pump, plus a £1,500 rural uplift (up to £9,000 in total) for eligible rural and island homes.
- Home Energy Scotland interest-free loan: an optional loan of up to £7,500 on top of the grant.
- Warm Homes Loan Scheme: low and zero-interest loans of up to £20,000 for an air-to-water heat pump, with some terms up to 30 years. It can be combined with Home Energy Scotland funding, and we’re proud to be part of the scheme. Read more in our Warm Homes Loan Scheme guide.
You must apply to Home Energy Scotland and receive a written offer before any work starts, and both the installer and the product must be MCS certified. The heat pump also has to provide all of your heating and hot water. The Boiler Upgrade Scheme you may have read about only applies in England and Wales. Our heat pump grant checker will tell you in a couple of minutes what you’re likely to be entitled to.
What Property Types Suit a Grant Aerona?
A Grant air source heat pump like the Aerona is especially strong in off-grid and oil-heated homes, which is a big part of the market here in Scotland. Grant UK has built oil boilers for decades, so many rural homeowners already know the name, and the Aerona 290’s 75°C flow temperature and 15.5kW top size suit the larger, older and harder-to-heat properties that are common off the gas grid.
Here’s how the range lines up with the homes we see most often:
- Rural and oil-heated homes: farmhouses and cottages in the Borders, Perthshire and West Lothian are a natural fit, and rural homes may qualify for the extra £1,500 Home Energy Scotland uplift. Our oil boiler vs air source heat pump comparison goes through the numbers in detail.
- Stone-built and older homes: solid-wall properties around Edinburgh, Linlithgow and Stirling often have higher heat loss. The higher flow temperature gives more breathing room, though some radiator upgrades still help keep running costs down.
- 1970s to 1990s family homes: cavity-walled semis and detached houses in places like Livingston, Dalkeith and Dunfermline usually suit the 6.5kW to 9kW models well, especially with good loft insulation.
- Small homes and new builds: the 4kW model, which modulates down to 1.25kW, suits well-insulated smaller properties that would be oversized by a bigger unit.
- Tenement and upper-floor flats: these are more difficult. As a monobloc unit using R290, the Aerona 290 needs outdoor space with clear protection zones around it, which many tenements simply don’t have.
Getting the size wrong costs money every winter, and our guide to what size heat pump you need in Scotland explains how we work it out. Placement is the other big consideration with any R290 unit, and our article on heat pump location rules covers what’s allowed.
One practical point: the 12kW and 15.5kW models draw up to 24.8A and 29.3A and need a 32A supply, so we always check your incoming electrics during the survey. Grant UK lists the range as “Connect and Notify” with the network operator, which usually keeps the paperwork straightforward.
Grant Aerona Maintenance Requirements
A Grant Aerona needs servicing once a year by a competent heat pump engineer, and Grant UK states that skipping the annual service will invalidate the product guarantee. Between services there’s very little for you to do beyond keeping the unit clear of leaves, snow and garden clutter.
Grant UK’s own service checklist for the Aerona includes:
- Clearing debris from the evaporator and fan outlet
- Checking the condensate drain is clear (important when the unit defrosts in cold weather)
- Checking hoses, insulation and for refrigerant leaks
- Testing the expansion vessel, pressure relief valve and system pressure
- Cleaning the magnetic filter
Units within 15 miles of the coast also get a protective evaporator spray, handy for homes in Musselburgh, Portobello or Kirkcaldy. Grant UK’s own ServicePlan costs £174.24 a year for the heat pump, or £275.88 including the cylinder, but you can also use your installer’s aftercare. We offer heat pump aftercare and servicing for the systems we fit.
Look after it and it should last. Grant UK says a correctly designed and installed heat pump system should last at least 15 years when serviced annually.
What Are the Ratings for Grant Heat Pumps?
Grant UK scores well on Trustpilot, with a 4.2 out of 5 TrustScore, although those reviews cover its oil boilers as well as its heat pumps. We couldn’t find a published Which? brand score for Grant heat pumps.
Trustpilot
When we checked in November 2026, Grant UK had a TrustScore of 4.2 out of 5 (“Great”) from around 2,600 reviews. About 77% were five-star and 7% one-star. Positive reviews praise professional engineers and reliable, quiet heating, while negative ones mention leaks, noise and slow support. Many relate to Grant oil boilers rather than Aerona heat pumps. Grant UK replies to all of its negative reviews, which is a good sign.
Which?
Which? doesn’t publish an openly available brand rating for Grant heat pumps that we could verify. Grant has previously won Which? Best Buy awards, but these were for its Vortex Pro Utility oil boilers (2017 to 2019) rather than its heat pumps. If you’re a Which? member, it’s worth checking its latest heat pump brand survey directly.
How Does Grant Aerona Compare?
The Grant Aerona 290 holds its own against the big names, and its 15.5kW top size gives it an edge for larger homes. Here’s a quick comparison with two other very popular brands we install.
| Feature | Grant Aerona 290 | Mitsubishi Ecodan R290 | Vaillant aroTHERM plus |
|---|---|---|---|
| Refrigerant | R290 | R290 | R290 |
| Sizes | 4kW to 15.5kW | 5kW to 12kW | 3.5kW to 12kW |
| Max flow temp | 75°C | 75°C | 75°C |
| Best known for | Rural and oil-replacement homes | Built in Livingston, widely installed | Strong all-rounder, smart controls |
All three are good heat pumps; the right one comes down to your home’s heat loss, siting and budget. Read our full Mitsubishi Ecodan review and Vaillant heat pump review for more detail.
Is a Grant Aerona Right for You?
A Grant Aerona is a great choice for rural, oil-heated or larger homes wanting a quiet, efficient heat pump. It’s less suited to homes with very limited outdoor space.
Choose Grant Aerona If…
- You’re replacing an oil or LPG boiler and want to move off delivered fuel for good
- Your home needs a bigger single unit, up to 15.5kW, on a single-phase supply
- You’d like to keep as many existing radiators as possible thanks to the 75°C flow temperature
- Quiet running matters, for example if the unit will sit near a bedroom or a neighbour’s garden
- You’re happy to have the system serviced every year to keep the 7-year guarantee
Don’t Choose Grant Aerona If…
- You live in a tenement or flat with no suitable outdoor space for an R290 monobloc unit
- You’d rather not commit to annual servicing
- You want a split system with a separate indoor unit, as the Aerona 290 is monobloc only
Get a Free Heat Pump Quote From The Edinburgh Boiler Company
As one of Scotland’s leading MCS-certified heat pump installers, we’ll survey your home, carry out a full heat loss calculation and recommend the right size and model for you, whether that’s a Grant Aerona or another brand. We cover Edinburgh, Musselburgh, Dalkeith, Penicuik, Livingston, Bathgate, Linlithgow, Falkirk, Stirling, Dunfermline, Kirkcaldy, Perth, Glasgow and the Borders.
We’ll also help with your Home Energy Scotland application and Warm Homes Loan options, so you know exactly what you’ll pay before work begins. Book your free heat pump survey or find out more about our heat pump installation service.
Grant Aerona Heat Pump FAQs
Is a “Grant heat pump” the same as a heat pump grant?
No. Grant UK is a heating manufacturer that makes the Aerona heat pumps reviewed here. Heat pump grants are funding schemes, and in Scotland the main one is the Home Energy Scotland grant of up to £7,500, or £9,000 with the rural uplift. You can use that funding towards a Grant Aerona, as the range is MCS accredited.
What is the difference between the Grant Aerona 290 and Aerona³?
The Aerona 290 is Grant UK’s newer fifth-generation heat pump using R290 refrigerant, reaching flow temperatures of up to 75°C. The Aerona³ is the previous generation using R32, with sizes of 6kW to 17kW and a lower 55°C heating set point.
How noisy is the Grant Aerona 290?
It’s quiet. Grant UK lists sound pressure of 40 to 46 dB(A) at 1 metre depending on the model, falling to 31 to 36 dB(A) at 3 metres, and every model is Quiet Mark approved.
Will a Grant Aerona work in a Scottish winter?
Yes. The Aerona 290 is rated to provide heating in outdoor temperatures down to -25°C, well below anything we normally see in central Scotland. It defrosts automatically when ice builds up, which is completely normal.
What warranty does a Grant Aerona come with?
Grant UK offers a 7-year guarantee when the heat pump is installed by a G1 installer who has completed Grant’s heat pump training, subject to terms and conditions. The heat pump must be serviced every year to keep the guarantee valid.
Can a Grant Aerona replace my oil boiler?
In most cases, yes. Replacing oil is one of the most common reasons people choose a Grant Aerona, and the 75°C flow temperature and sizes up to 15.5kW suit larger rural homes. A heat loss survey will confirm the right size and whether any radiators need upgrading.
