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Octopus Cosy 6 Air Source Heat Pump
Octopus's 6kW air source heat pump for typical 1–4 bed UK homes (heat loss <5.6kW). R290 refrigerant, 8-year warranty, ~£4,460 fitted after BUS grant.
4.3 / 5
☆☆☆☆☆
★★★★★
Pros
- All-in installed cost typically £4,460 after the £7,500 Boiler Upgrade Scheme grant — among the most price-transparent UK heat pump packages
- R290 natural refrigerant (GWP of 3) — future-proof against the F-gas regulation tightening that will hit R32-based competitors
- Generous warranty: 8-year product cover plus 5-year labour, both backed by Octopus directly rather than a third-party installer
- Compact 855mm × 1125mm outdoor unit — fits awkward UK side returns where larger units would not pass clearance rules
- Single point of contact: survey, install, monitoring, repair, and tariff all handled by Octopus — no installer / manufacturer / energy-supplier coordination loop
Cons
- SCOP 3.4 at 50°C flow / 2.8 at 65°C flow — mid-range efficiency; older homes that can't run at low flow temperatures will see noticeably higher running costs than published headline figures imply
- Cosy 6 caps at properties with measured heat loss below 5.6kW. Many UK semis and detached homes (especially pre-1990s with limited insulation upgrades) need the Cosy 9 or Cosy 12 instead
- Hardware can only be bought through Octopus's install service — you cannot have an independent installer fit a Cosy 6 if you prefer your own tradesperson
- Annual service plan is an extra £9/month — adds £108/year on top of the headline price
- Cosy Pods are basic temperature/humidity sensors, not a full smart-thermostat replacement; integrators wanting Honeywell / tado° / Hive controls will need additional kit
Specifications
| Specification | Value |
|---|---|
| Heating capacity | 6kW (suits homes with heat loss under 5.6kW) |
| Refrigerant | R290 (propane, GWP 3) |
| SCOP at 50°C flow | 3.4 |
| SCOP at 65°C flow | 2.8 |
| Sound power | 58–60 dB(A) LWA |
| Outdoor unit dimensions | 855mm W × 1125mm H |
| Warranty | 8-year product, 5-year labour |
| Hot water cylinder | Included in install |
| Cosy Pods | Up to 4 included (temperature + humidity) |
| Eligible BUS grant | £7,500 |
| Typical net price after BUS | £4,460 |