Sinclair SCV-EB Series Service Manual page 57

5.13 H1 Troubleshooting
5.13.1 Digital display output
5.13.2 Description
 Communication malfunction between main control board and inverter board
 Heat pump stops running.
 Error code is displayed on the refrigerant system PCB digital tube and user interface..

5.13.3 Procedure
The digital tube of refrigerant system PCB
and the diode light of IPM module are
The digital tube is lighting, but the diode
Replace refrigerant system PCB and or
H1
not lighting
No
is not lighting.
No
IPM module
Yes
Check the power supply
Check whether the IPM power input
Yes
cable is loose
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