Viessmann Vitocal 350-G (34.7 kW)

Specifications and technical data

Also known as: BWS 351.B27

✓ BUS eligibleGround Source (GSHP)ResidentialR410A34.7 kW

Manufacturer	Viessmann
Model	Vitocal 350-G
Model code	BW 351.B27
Heat pump type	Ground Source (GSHP) All Ground Source heat pumps →
Application	Residential All Residential heat pumps →
Refrigerant	R410A All R410A heat pumps →
Mode	Heating only
Heating capacity	34.7 kW
Max heating output (low temp)	28.7 kW at B0/W35
COP (heating)	4.9 at B0/W35
Operating range (air)	-10 to 25 °C
Heating flow temperature	up to 70 °C
Electrical supply	380-415V (Three Phase)
Dimensions (H×W×D)	1267 × 780 × 1085 mm
Operational Weight	285 kg
Sound power level	52 dB(A) (Sound Power LW(A))
Data added	2026-09-26
Data source	Manufacturer documentation (Viessmann)
Verification	Verified by a human
Boiler Upgrade Scheme	✓ BUS eligible — Listed on the Ofgem BUS Product Eligibility List (24 Sep 2026). Grant also needs an MCS-certified installer and a qualifying system design. Funding guide
PEL certificate no.	BSI KM 554512/16/2
MCS certification	✓ MCS listed
MCS certificate no.	BSI KM 554512/16/2; BSI KM 554512/16/6

Free data sheet (PDF) →

View manufacturer page →

Viessmann Vitocal 350-G BW 351.B27, brine-to-water heat pump, R410A. 28.7 kW at B0/W35 with a COP of 4.9. Flow to 70 C.

Where to buy (UK)

UK Supplier	Secon Renewables
UK Supplier	Pirate Heating Supplies
UK Supplier	Beet BG
UK Supplier	GetPlumb
UK Supplier	Solar Trading

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Data is compiled from manufacturer sources and may contain errors or gaps. Always confirm specifications with the manufacturer before making decisions.