Big house? High heat loss? This is your heat pump.
Get the Grant Aerona 290 15.5kW heat pump with Octopus
The Grant Aerona 290 15.5kW air source heat pump is designed for larger homes or properties with higher heat loss. It’s manufactured by Grant UK, a British heating specialist with over 40 years’ experience.
And just like our range of Cosy heat pumps, it’s efficient, smart and uses R290 refrigerant, which is far less harmful to the planet.
With a Grant Aerona 290 you’ll get the same great Octopus installation experience, just with a slightly bigger heat pump.
Key features & benefits
Built for higher heat loss
15.5kW output which compliments our existing Cosy heat pump range above a 11.2KW heat loss.
Efficient & sustainable
A+++ energy efficiency rating and uses natural R290 refrigerant, which has a much lower environmental impact than traditional alternatives.
Eligible for up to £9,000 off with the government grant
MCS certified, making it eligible for the Boiler Upgrade Scheme (we’ll sort the paperwork!).
Designed for reliability
Built-in safety systems to protect pressure and temperature.
Smart heating controls
Installed with the Aerona Smart Controller with app control so you keep things running smoothly from your smart phone.
Ultra-quiet
Quiet Mark accredited and among the quietest heat pumps in its class.
Controls & app
Aerona Smart Controller
A simple, user-friendly black wall-mounted control system that lets you:
Set and adjust heating and hot water schedules
Use daily or weekly timed programming
Optimise efficiency with weather compensation
App & remote access
Access remotely online or via a dedicated app
Control your heating from anywhere thanks to the supplied Wi-Fi hub
Looked after, long after install day
Installation by trusted engineers
No matter the type of heat pump we install, you’re in safe tentacles - our engineers are fully backed by Which? Trusted Trader.
Warranty & aftercare
With a Grant Aerona 290 you’ll get a 8-year warranty which’ll require you to book a yearly service. Once installed, you’ll be fully supported by our aftercare team 7 days a week.
Want to talk it over?
Ask us about spreading the cost with monthly payments
Upgrade to cosy, cleaner, cost-efficient heating with flexible payment options over 3-15 year
Frequently asked questions
The Grant Aerona 290 15.5kW is designed for homes with higher heat loss. We’ll recommend this heat pump for your home if the property is larger, older, or simply harder to heat.
Our current range of Cosy heat pumps are suited to homes with a heat loss below 11.2kW. By offering the Grant Aerona 290 15.5kW we can help more homes switch to smarter, cleaner heating by getting a heat pump.
Yes — the Grant Aerona heat pump is MCS certified, meaning it qualifies for the Boiler Upgrade Scheme subject to standard eligibility criteria.
Our new Grant Aerona heat pump is only for heat losses above 11.2KW. Our current range of heat pumps, including the Cosy will be offered for those heat losses less than 11.2kW.
Yes - the Grant Aerona works with all the same Octopus tariffs as our other heat pumps — including Cosy Octopus, so you can benefit from 8 hours of super cheap electricity a day to warm your home.
Cosy heat pump customers on the Cosy Octopus tariff saved an average of £224 last year compared to using a gas boiler running at 85% efficiency on our standard variable tariff
This figure is based on the actual energy consumption of all Cosy heat pump customers on a Cosy Octopus tariff between 1 July 2025 and 1 July 2026, using tariff rates at the time.
We compared this to the cost of producing the same amount of heat with a gas boiler operating at 85% efficiency, priced using our Flexible Octopus (standard variable) tariff at the same time.
Savings from gas standing charges were included only for customers who had fully removed their gas supply (less than 3% of customers). Actual savings vary depending on system design, tariff choice, home insulation, and energy use.
Our typical heat pump price is £4,459, which is lower than the national average of £5,600
This is the median post-survey price from all of our heat pump quotes after the £7,500 Boiler Upgrade Scheme has been applied, between 01/09/2025 and 28/02/2026. The national average is taken from the Boiler Upgrade Scheme statistics: April 2026 – median cost of installation Q4 2025.
Cut carbon emissions by 82% with a heat pump
This is the typical reduction in heating carbon emissions using an electric powered heat pump compared to a gas boiler.
The carbon breakdown
Gas CO2 (tonnes per year) - 2.42
Electricity CO2 (tonnes per year) - 0.43
Carbon saving (tonnes per year) - 1.99
Data sources and assumptions
Gas Energy Usage (kWh) 11500 (Ofgem medium use gas usage (Jun 2026))
Heat Pump Efficiency 312% (typical seasonal coefficient of performance from a fleet of Octopus high temperature heat pumps)
Gas Boiler Efficiency 85% (The typical gas boiler efficiency from a BEIS study)
Gas fuel emissions of (gCO2/kWh) 210 (SAP 10.2)
Electricity fuel emissions of (gCO2/kWh) 136 (SAP 10.2)
Based on these sources, heat pumps typically produce lower operational emissions when heating the home than gas boilers.
For more information, explore our Octopus Cosy heat pump fleet performance dashboard.
We're the largest heat pump installer on the Boiler Upgrade Scheme
Based on Octopus benchmarking against Ofgem reports from 2024, and we've continued to grow since.
Our customers love their heat pumps!
- 93% of people say it's the same or more comfortable than their previous boiler
- 87% say it costs the same to run or less
- 83% say it's the same noise or less than the previous boiler
- 90% say it's just as easy or easier to maintain
We survey all our heat pump customers 3 months post-installation to see how they find their heat pump compared to their previous gas boiler. Survey results are taken from a sample of 2,837 customers:
Comfort: 93% of people say it is the same or more comfortable than their previous boiler.
Running Costs: 87% say it costs the same to run or less.
Noise: 83% say it is the same noise or less than the previous boiler.
Maintenance: 90% say it is just as easy or easier to maintain.
A heat pump is around 4x more efficient than a gas boiler
Heat pumps don't generate heat by burning fuel. Instead, they transfer existing heat into your home. This means they can deliver multiple units of heat for each unit of electricity used.
Based on performance data from a fleet of installed Octopus Cosy heat pumps, typical real-world seasonal performance (SPF or SCOP) is around 3.6. This means around 3–4 kWh of heat is delivered for every 1 kWh of electricity used (an effective efficiency of 300–400%). By comparison, typical UK domestic gas boilers operate at around 85% efficiency, delivering approximately 0.85 kWh of heat per 1 kWh of gas used. On this basis, a heat pump can be around 4× more efficient than a typical gas boiler.
All our heat pumps are independently tested by the Building Research Establishment (BRE), with SCOP values published on the Microgeneration Certification Scheme (MCS) product database. Actual efficiency will vary depending on the property, system design, and usage. For more information, explore our Octopus Cosy heat pump fleet performance dashboard.
The UK's most awarded energy supplier
We've won more awards for customer service than anyone else.
Heat pumps give reliable, consistent heating and hot water
The heat pump user survey report by Nesta from May 2023 summarises that "users are highly satisfied with their heat pumps". It states: "People living in England, Scotland and Wales who own their home and use a heat pump to heat it are satisfied that heat pumps are safe, reliable, quiet heat sources that are effective for space heating and producing hot water." Find the full report here.
The Cosy heat pump is quiet
Heat pump sound power levels are verified by an independent, third-party laboratory as part of the testing process for inclusion on the MCS product database. The laboratory verifies the sound power on the A-weighted decibel curve, as A-weighting closely aligns to how humans perceive "loudness".
All heat pumps are measured using EN14511 standards to ensure uniformity across manufacturers and models. Our Cosy 6 heat pump has a verified sound power level lower than many other heat pumps of the same capacity.
Heat pump heating makes the air healthier in your home
Homes with a heat pump emit far less harmful nitrous oxide (NOx) emissions than those with gas boilers and cookers, significantly reducing asthma and other respiratory illnesses. According to the Sustainable Markets Initiative Cleantech Homes report.
A heat pump can add thousands to your property value
Analysis by the Department of Land Economy at the University of Cambridge suggests a 16% value uplift for new-build homes with enough solar and battery storage to eliminate energy bills. A further study of over five million existing properties indicates a 2-3% value increase for existing homes with solar panels or heat pumps (versus like-for-like gas-heated homes), according to the Sustainable Markets Initiative: Cleantech Homes report, 2024.
As of April 2025, the average house price in the UK is £265,497 according to the Land Registry. Therefore, a 2-3% value increase for an average house priced at £265,497 would be between £5,310 and £7,965.
Heat pumps typically last longer than gas boilers
The expected lifespan of a typical gas boiler is 10–15 years. A heat pump typically has a lifespan of 15–20 years, with UK government research indicating an average of around 20 years. Manufacturer Daikin reports similar ranges. Actual lifespan depends on factors such as installation quality, maintenance, usage patterns, and operating conditions.