heatpumpdatabaseProduct data sheetheatpumpdatabase.com
Vaillant flexoTHERM exclusive
Model code: VWF 157/4 + VWW 19/4 SI
✓ BUS eligible✓ MCS listedWater Source (WSHP)ResidentialHeating only
Heating capacity
16.92 kW
SCOP
5.82
W35
COP
5.36
W10/W35
Max flow temp
65°C
Sound power
49.9 dB(A)
Refrigerant
R410A
Boiler Upgrade Scheme
✓ BUS eligible
Listed on the Ofgem BUS Product Eligibility List (24 Sep 2026).
PEL certificate: KIWA 00023/012 HP
Grant also needs an MCS-certified installer and a qualifying system design.
MCS certification
✓ MCS listed
Certificate: KIWA 00023/012 HP
| General | |
|---|---|
| Heat pump type | Water Source (WSHP) |
| Application | Residential |
| Refrigerant | R410A |
| Mode | Heating only |
| Heating performance | |
| Heating capacity | 16.92 kW |
| Max heating output (low temp) | 16.92 kW at W10/W55 |
| COP (heating) | 5.36 at W10/W35 |
| SCOP (heating) | 5.82 at W35 |
| Heating flow temperature | up to 65 °C |
| Electrical, acoustic and physical | |
| Electrical supply | 380-415V (Three Phase) |
| Sound power level | 49.9 dB(A) (Sound Power LW(A)) |
| Dimensions (H×W×D) | 1183 × 595 × 600 mm |
| Operational Weight | 176 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.