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Stiebel Eltron WPL ACS classic
Model code: WPL 09 ACS classic
✓ BUS eligibleAir Source (ASHP)ResidentialHeating & cooling
Heating capacity
4.06 kW
SCOP
4.15
W35
COP
4.54
A7/W35
Max flow temp
60°C
Sound power
52 dB(A)
Refrigerant
R410A
Boiler Upgrade Scheme
✓ BUS eligible
Listed on the Ofgem BUS Product Eligibility List (24 Sep 2026).
PEL certificate: 011-1W0061_1
Grant also needs an MCS-certified installer and a qualifying system design.
MCS certification
No MCS listing recorded.
| General | |
|---|---|
| Heat pump type | Air Source (ASHP) |
| Application | Residential |
| Refrigerant | R410A |
| Mode | Heating & cooling |
| Heating performance | |
| Heating capacity | 4.06 kW |
| Max heating output (low temp) | 4.06 kW at A-7/W35 |
| COP (heating) | 4.54 at A7/W35 |
| SCOP (heating) | 4.15 at W35 |
| Operating range (air) | -20 to 40 °C |
| Heating flow temperature | up to 60 °C |
| Electrical, acoustic and physical | |
| Electrical supply | 220-240V (Single Phase) |
| Sound power level | 52 dB(A) (Sound Power LW(A)) |
| Dimensions (H×W×D) | 740 × 1022 × 524 mm |
| Operational Weight | 62 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.