Octopus Cosy Air Source Heat Pump Cost in South East England
£8,000 to £12,000 installed before the grant, or £500 to £4,500 after a £7,500 grant.
Prices are PumpSwap's indicative figures for Octopus Cosy, not quotes. Boiler Upgrade Scheme grant (£9,000 for off-gas homes on oil or LPG).
Octopus Energy's own heat pump, designed and built in the UK at its factory in Craigavon, Northern Ireland, and installed by Octopus or its Cosy Accredited Installers. Octopus says its median quote was £4,064 after the £7,500 grant (quotes from 1 June to 30 September 2026). It pairs with the Cosy Octopus tariff, which works with any heat pump.
Octopus Cosy models and running costs in South East England
Running costs for 10,000 kWh of heat a year at 26.88p per kWh (Ofgem price cap for South Eastern England, 1 October to 31 December 2026), at a 45°C design flow temperature: the midpoint of each model's MCS-certified 35°C and 55°C SCOPs.
| Model | Size | SCOP 35°C / 55°C | Installed, before grant | Running cost a year |
|---|---|---|---|---|
| Cosy 6 2-3 bed homes | 6 kW | 4.31 / 3.23 | £8,000 to £11,000 | £715 |
| Cosy 9 3-4 bed homes | 9 kW | 4.36 / 3.43 | £9,000 to £12,000 | £690 |
Pros
- Octopus median quote £4,064 after the grant (June to September 2026)
- Designed and built in the UK
- 8-year hardware warranty as standard
- Your installer handles the grant paperwork
Cons
- Only available through Octopus or its accredited installers
- Newer hardware: Cosy 6 launched in late 2023, Cosy 9 in 2025
Best for: Price-led switchers happy to buy and install through Octopus. Warranty: 8 years.
What South East England means for your heat pump
- Climate. January averages 7.8°C by day and 1.9°C at night, with 43 days of air frost a year (Met Office 1991-2020; UK 1.2°C and 53 days). The heat loss survey sizes the unit for your local design temperature.
- Gas grid. 16% of homes here are off the gas grid (2024 estimate; Great Britain 16%). Homes on oil or LPG with no mains gas can claim £9,000 until 31 March 2027.
- Grant. Boiler Upgrade Scheme grant (£9,000 for off-gas homes on oil or LPG).
Full detail for the region, including planning rules and running costs against gas: air source heat pump cost in South East England.
Octopus Cosy prices in towns across South East England
Other brands in South East England
Octopus Cosy in other regions: London, South West England, East of England, East Midlands, West Midlands, Yorkshire and the Humber, North West England, North East England, Scotland, Wales.
Frequently asked questions
How much does a Octopus Cosy heat pump cost in South East England?
£8,000 to £12,000 installed before the grant, or £500 to £4,500 after a £7,500 grant. These are PumpSwap's indicative 2026 prices; your installer's survey sets the real figure.
Can I get the grant on a Octopus Cosy heat pump in South East England?
Yes, if your home qualifies: the Boiler Upgrade Scheme is not tied to a brand, as long as the installer is MCS-certified (Octopus claims it for you on its own installs). It comes straight off the quote.
What would a Octopus Cosy heat pump cost to run in South East England?
Roughly £690 a year for the Cosy 9 to deliver 10,000 kWh of heat at 26.88p per kWh (Ofgem price cap for South Eastern England, 1 October to 31 December 2026). That assumes a 45°C design flow temperature, estimated from its MCS-certified SCOPs of 4.36 at 35°C and 3.43 at 55°C. A lower flow temperature, with bigger radiators or underfloor heating, costs less to run.
Who installs Octopus Cosy heat pumps in South East England?
Octopus Cosy is installed by Octopus Energy or its Cosy Accredited Installers, not by independent installers generally. For comparison quotes on other brands, PumpSwap puts you in touch with local MCS-certified installers.
Heat pump guides for South East England
- Air source heat pump cost in South East England
- Heat pump grants in South East England and how to claim them
- Air source heat pump installers in South East England
- Air source heat pump installation cost in the UK
- The best air source heat pumps in the UK, compared
- The £7,500 Boiler Upgrade Scheme, explained
Prices, models, efficiency and warranties are indicative and change; confirm with your MCS-certified installer. Climate: Met Office 1991-2020 averages. Energy prices: Ofgem price cap for South Eastern England, 1 October to 31 December 2026.
Where are you?
See indicative costs and local installers for your area