If you’ve been looking into heat pumps lately, you’ve probably noticed that not all of them are built the same. Some are complicated, noisy, or just not right for the average UK home. The Grant Aerona³ is different. It’s a quietly impressive piece of kit that’s been winning over homeowners and heating engineers alike — and for good reason.
At Clever Energy Boilers, we install Grant heat pumps range across the North West, Yorkshire and the Midlands. This review covers everything you need to know before you decide whether a Grant heat pump is the right call for your home.
Review of the Grant Aerona³ Air Source Heat Pump Range
The Aerona³ is an air source heat pump — which means it pulls heat from the outside air and uses it to warm your home and hot water. Even on a cold winter morning, there’s enough heat energy in the air to make it work efficiently. You’re not burning gas or oil; you’re moving heat that’s already there.
Grant is a well-established British heating brand with roots in the oil boiler market. They’ve been manufacturing heating systems since the 1970s, and the Aerona³ reflects that engineering heritage. It runs on R32 refrigerant — a modern, low Global Warming Potential refrigerant that’s cleaner than the older R410A used in previous generations.
The unit sits entirely outside your home. Inside, you’ll need a hot water cylinder and some pipework connecting to your radiators or underfloor heating. That’s it. No gas supply, no flue, no combustion.
Grant Aerona³ Range Overview: Models and Output
Grant currently offers four Aerona³ R32 models. Here’s how they break down and what kind of home each one suits:
All four are A+++ rated for space heating — the highest energy efficiency class available. The sweet spot for most homes tends to be the 10kW or 13kW, which cover a wide range of properties and offer the strongest SCOP figures in the range.
Grant Heat Pump Efficiency Ratings SCOP & COP Details
Efficiency matters because it directly affects your bills. Heat pumps are measured by their SCOP — Seasonal Coefficient of Performance — which tells you how many units of heat you get for every unit of electricity you put in.
The Grant Aerona³ 13kW achieves a SCOP of around 5.4 at a 35°C flow temperature. In plain terms, for every £1 you spend on electricity, you’re getting the equivalent of around £5.40 worth of heat. That’s not possible with any gas or oil boiler. Even the best condensing boiler tops out at around 93–95% efficiency — meaning £0.93 for every £1 spent. The maths are compelling.
That said, efficiency is closely tied to your flow temperature. The lower the flow temperature your system runs at — typically 35–45°C — the better the heat pump performs. Homes with underfloor heating or upgraded, oversized radiators will consistently get the best results.
Grant Air Source Heat Pump Running Costs Pay Per Year
This is the question everyone asks. The honest answer is: it depends on your current heating setup, your tariff, and how well your home retains heat.
Here’s a realistic picture for a typical four-bedroom detached home in the North of England, moving from gas to a heat pump:
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Gas central heating running costs: approximately £1,200–£1,800 per year at current rates
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Grant Aerona³ heat pump running costs: approximately £900–£1,400 per year on a standard electricity tariff
The gap narrows further when you move to a heat pump electricity tariff such as Octopus Cosy or a similar time-of-use rate, where off-peak units cost significantly less. Some households running optimised systems report savings of 30–40% on annual heating bills compared to their old gas or oil system — particularly those switching from oil boilers.
A heat pump running on the UK grid produces around 60–75% less carbon than a gas boiler today, and that figure improves every year as the grid gets greener.
Grant Air Source Heat Pump Installation Cost Prices, Grants & What You’ll Actually Pay
A fully installed Grant Aerona³ system typically costs between £9,000 and £14,000 depending on model size, cylinder choice, radiator upgrades and any property-specific groundwork.
Before the grant, that’s a significant investment. But here’s where it changes significantly.
How Much Is the Boiler Upgrade Scheme Grant for a Heat Pump?
Eligible homeowners can claim a £7,500 government grant through the Boiler Upgrade Scheme (BUS), applied directly by your MCS-certified installer. You never have to handle the money yourself — it comes straight off your quote before you pay.
That means the net cost for many Grant Aerona³ installations is effectively £1,500 to £6,500 out of pocket, depending on system scope. For rural properties, the grant increases to £9,000 under the rural uplift.
At Clever Energy Boilers, we’re MCS certified, which means we can apply for the grant on your behalf as part of the installation process. We also offer flexible payment options to help spread any remaining costs.
What Does a Grant Air Source Heat Pump Installation Include?
This is where the Aerona³ earns extra credit. As a monobloc system, all the refrigerant components are housed in the single outdoor unit. That removes the need for specialist on-site refrigerant handling, simplifies the installation and keeps your project on schedule.
Here’s what a typical installation with Clever Energy Boilers looks like:
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Heat loss survey — We calculate exactly how much heat your home loses and size the right model for you. This is a full room-by-room assessment to MCS standards, not a rough estimate.
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System design — We plan the cylinder, controls and emitter setup. If your radiators need upsizing, we’ll tell you exactly what’s needed and at what cost before any work begins.
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Installation day(s) — The outdoor unit is mounted on a purpose-built slab or wall bracket. Internal pipework connects to your cylinder, and controls are fully commissioned.
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Grant registration — We register the installation on the MCS database and process your BUS grant application on your behalf.
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Handover and setup — We walk you through the controls, set your heating schedules and explain how to get the best efficiency from your system day to day.
Most straightforward installations are completed in two to three days.
Grant Aerona³ Noise Levels: Is It Quiet Enough for a Residential Garden?
One concern that comes up regularly is noise. The Grant Aerona³ 13kW and 17kW models have both received the Quiet Mark — an independent certification recognising them as among the quieter heat pumps in their class.
Noise levels across the range run at roughly 50–54dB(A) at one metre. To put that into context, that’s broadly similar to a quiet conversation or a running fridge freezer. Correctly sited away from bedroom windows or neighbouring walls, most homeowners simply stop noticing it within a matter of days.
The 6kW and 10kW units are notably compact — roughly the size of a small chest freezer — which helps on tighter plots, side-access gardens and smaller rear yards common across Yorkshire and the Midlands.
Grant Heat Pump Controls, Smart Heating and Weather Compensation
Aerona³ units are compatible with S-Plan and Y-Plan heating systems, so they integrate cleanly with most standard UK heating layouts — both radiator circuits and underfloor heating.
Grant’s smart controller kit enables remote scheduling, weather compensation, hot water programmes and pairing with third-party optimisers such as Homely, which can reduce running costs further by shifting heat demand to cheaper tariff windows.
Rather than running at a fixed output regardless of outdoor temperature, the system modulates — turning down when it’s mild, turning up when it gets cold. This keeps the system efficient year-round and avoids unnecessary energy use on warmer autumn or spring days.
Grant Air Source Heat Pump Warranty: How Long Is the Cover?
Standard cover on Aerona³ R32 units starts at two to five years depending on the supplier and registration. However, when installed by a Grant G1 registered partner, the warranty extends to up to seven years on the unit itself.
That’s a meaningful difference. Seven years of manufacturer-backed cover on an outdoor unit exposed to UK weather is a strong commitment from Grant, and it’s one of the clearest differentiators when customers are comparing heat pump brands side by side.
Regular annual servicing helps maintain that warranty and keeps the system running at peak efficiency throughout its lifespan, which is typically 15–20 years.
How a Grant Heat Pump Installation Affects Your Property Value and EPC Rating
Something that doesn’t always come up in heat pump conversations is what the installation does to your property. Valuers and estate agents are increasingly recognising homes with low-carbon heating systems as more desirable — particularly as EPC regulations tighten and mortgage lenders begin offering green mortgage incentives.
A property with an MCS-certified heat pump installation and an improved EPC band — typically moving from a D or E up to a C or above when combined with insulation improvements — can attract a measurable premium at sale. Buyers thinking about long-term running costs increasingly see a heat pump as an asset rather than an unknown.
Across parts of Yorkshire, the North West and the Midlands, older housing stock — Victorian terraces, 1950s semi-detached homes, rural stone cottages — is exactly the type of property that benefits most from a properly designed low-temperature heat pump system, both on paper and in practice.
There’s also the question of future-proofing. The UK government has set a binding target to phase out new gas boiler sales by 2035. Homeowners who install now are a decade ahead of that deadline, avoiding both the premium cost of late adoption and the regulatory uncertainty that comes with staying on gas.
Who Is the Grant Aerona³ Best For? Ideal Homes and Use Cases
The Aerona³ range is a strong fit for:
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Detached and semi-detached homes across the North of England, particularly those coming off oil, LPG or ageing gas systems
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Homes with existing or planned underfloor heating, where low flow temperatures are already the norm
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Homeowners wanting to claim the BUS grant with a proven, MCS-eligible system installed by a certified partner
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Properties in rural areas where oil costs have made heating expensive and unpredictable year to year
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Homeowners prioritising quiet, reliable, low-maintenance operation over cutting-edge app features
It’s not the most feature-rich system on the market. But it’s reliable, well-supported, quiet, and backed by a brand with genuine UK engineering heritage. For a lot of customers, that matters more than a polished app interface.
Grant Air Source Heat Pump FAQs
Can a Grant Heat Pump Work With My Existing Radiators?
In some cases yes, but it depends on the size of your radiators and the heat-loss calculation for your home. Our survey team will calculate exactly what’s needed. Some homes need radiator upgrades; many don’t.
How Long Does a Grant Aerona³ Heat Pump Last?
Typically 15–20 years with proper annual servicing. The outdoor unit contains few moving parts beyond the inverter compressor and fan, which significantly reduces wear-related failure risk compared to a gas boiler.
Do I Need Planning Permission to Install a Grant Heat Pump?
Most domestic air source heat pump installations are covered by permitted development rights and don’t require planning permission, provided they meet certain conditions around size and siting. We’ll confirm this during your survey.
What Is the Grant Heat Pump Installation Cost After the BUS Grant?
After the £7,500 Boiler Upgrade Scheme grant, most homeowners pay a net cost of between £1,500 and £6,500 depending on the model size and full system scope. Rural properties may qualify for a higher £9,000 grant.
Will a Grant Heat Pump Work Efficiently in Winter?
Yes. The Aerona³ is designed to operate efficiently down to outdoor temperatures of around -15°C to -20°C. In a typical UK winter, performance remains strong throughout.
How Do I Qualify for the Boiler Upgrade Scheme Grant?
You need to own the property, have a valid EPC with no outstanding recommendations for loft or cavity wall insulation, and use an MCS-certified installer. Clever Energy Boilers will handle the application for you.
Thinking about a Grant heat pump installation? Clever Energy Boilers offer a full, no-obligation heat loss survey across the North West, Yorkshire and the Midlands. Get your fixed-price quote today.
