Hitachi FS3 Series, Service Manual, Page: 20 / 240

1
12
TROUBLESHOOTING
1.1.7 ABNORMALITIES OF DEVICES (Cont.)
Phenomenon Cause Check Item
Action
(Turn OFF main switch)
Failure of
Thermistor
Failure of
Discharge
Air Temp.
Thermistor
Disconnected
Wire of
Thermistor
Check Thermistor by self-
checking *2)
Replace or correctly
connect wiring when it is
abnormal
Failure of Remote Control
Switch
Replace if failed
Indoor Fan
Speed is not
Changed
Failure of PCB for Indoor Unit
Check it by self-checking
*1)
Replace if PCB is failed
Failure of
Thermistor
Failure of
Thermistor for
Outdoor
Evaporating
Temp. during
Heating
Disconnected
Wire of
Thermistor
Replace or correctly
connect when it is
abnormal.
Disconnected
4-Way Valve
Coil
Measure resistance of coil
Failure of
4-Way Valve
º
Incorrect
Activation of
4-way valve
Enforced power supply.
Replace 4-Way valve
Disconnected Control Wires
between Indoor Unit and
Outdoor Unit
Check connectors Correctly connect wiring.
Disconnected
Wiring to
PCB
Check connectors Correctly connect wiring
Failure of
Outdoor
units of PCB
Failure of
PCB
Check PCB by self-
checking *1).
Replace it when check
mode is not available.
Disconnected
Wiring to
PCB
Check connectors Correctly connect wiring
No Defrosting
Operation Mode
is Available
during Heating
Operation or
Defrosting
Operation is
Continued
Failure of
Indoor Unit
of PCB
Failure of
PCB
Light and LCD
Indication on
Remote Control
Switch are kept
ON
Failure of PCB in Indoor Unit
or Remote Control Switch
Check PCB by self-
checking *1).
Replace if PCB is failed
*1): Refer to Item 1.3.1~1.3.4.
*2): Refer to Item 1.3.1.