520 Indoor / 520 Outdoor Service Manual
Ver. 1.00
51
CONFIDENTIAL
Error Code
Malfunction description
Cancellation method
661
Water control valve fault
(Bypass valve function)
Turn off the power or water supply
Diagnosis
Checkpoint
1 PCB and bypass valve fault
(Refer to section 10-11 & 10-18)
Visual inspection of Water control valve: connection/breakage of wires,
motor drive locked due to scale buildup, and/or water leakage.
Normal: 13.0 to 16 VDC between (blue-brown)
Normal: ON: 12.5 to 16.0 VDC / OFF: 0 to 1 V
Normal: 1V Less than (0
˚
position)
Visual inspection PCB: connection/breakage of wires and/or burn marks on
the computer board.
J
Error Code
Malfunction description
Cancellation method
701
1 PCB fault
[1] Fault of preparation for the mixing thermistor
operation.
[2] Fault of driving circuit for Gas Proportional
Valve(VG
0
)
Turn off the power or water supply
Diagnosis
Checkpoint
1 Check the PCB and/or gas proportional valve
(Refer to section 10-5 & 10-18)
Visual inspection PCB: connection/breakage of wires and/or burn marks on
the computer board.
Visual inspection gas proportional valve: connection/breakage of wires of
the gas proportional valve.
Normal: 20 to 40
Ω
between (white) & (red)
H1