CTC GSi 12 (1.6–10 kW)

Specifications and technical data

✓ BUS eligibleGround Source (GSHP)ResidentialR407C1.6–10 kW

Manufacturer	CTC
Model	GSi 12
Model code	CTC GSi 12 (1 phase)
Heat pump type	Ground Source (GSHP) All Ground Source heat pumps →
Application	Residential All Residential heat pumps →
Refrigerant	R407C All R407C heat pumps →
Mode	Heating only
Heating capacity	1.6–10 kW
Max heating output (low temp)	5.4 kW at B0/W55
COP (heating)	4.78 at B0/W35
SCOP (heating)	5.1 at W35
Electrical supply	220-240V (Single Phase)
Dimensions (H×W×D)	1910 × 596 × 673 mm
Operational Weight	252 kg
Sound power level	38 dB(A) (Sound Power LW(A))
Data added	2026-10-20
Data source	CTC GSi 12/16 brochure (technical data), cross-checked with CTC Technical Data 2019
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.	MCS HP0023/55
MCS certification	✓ MCS listed
MCS certificate no.	MCS HP0023/55

Free data sheet (PDF) →

CTC GSi 12 speed-controlled ground source heat pump with integrated 223 L hot water cylinder, R407C, single-phase.

Where to buy (UK)

UK Supplier	The Heat Pump Warehouse

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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.