heatpumpdatabaseProduct data sheetheatpumpdatabase.com
Nibe S1255
Model code: S1255-12
✓ BUS eligible✓ MCS listedGround Source (GSHP)ResidentialHeating only
Heating capacity
3–12 kW
SCOP
5.2
W35
COP
4.87
B0/W35
Max flow temp
70°C
Sound power
47 dB(A)
Refrigerant
R407C
Boiler Upgrade Scheme
✓ BUS eligible
Listed on the Ofgem BUS Product Eligibility List (24 Sep 2026).
PEL certificate: 012-SC0191-19-2
Grant also needs an MCS-certified installer and a qualifying system design.
MCS certification
✓ MCS listed
Certificate: 012-SC0191-19-2
| General | |
|---|---|
| Heat pump type | Ground Source (GSHP) |
| Application | Residential |
| Refrigerant | R407C |
| Mode | Heating only |
| Heating performance | |
| Heating capacity | 3–12 kW |
| Max heating output (low temp) | 5.06 kW at B0/W35 |
| COP (heating) | 4.87 at B0/W35 |
| SCOP (heating) | 5.2 at W35 |
| Operating range (air) | -8 to 30 °C |
| Heating flow temperature | 20–70 °C |
| Electrical, acoustic and physical | |
| Electrical supply | 220-240V (Single Phase) |
| Sound power level | 47 dB(A) (Sound Power LW(A)) |
| Dimensions (H×W×D) | 1800 × 600 × 620 mm |
| Operational Weight | 213 kg |
Test conditions: A = outdoor air °C, W = flow water °C (e.g. A7/W35 = 7°C air, 35°C flow). Compare COP and SCOP only at the same conditions.