Westinghouse WHU09DHA21S Service Manual page 42

Fault
Fault description
code
Indoor EEPROM
74
Data 2 fault
Indoor ambient
81 Temperature
Sensor Fault
Evaporator Middle
83 Temperature
Sensor Fault
Communication
between main
control board &
FE
Wired controller
(254)
Fault (display on
wired controller)
Communication
between main
control board
ER
& display board
Fault (displays on
display board)
Possible reasons f or abnormality
EE in MCU fails, the unit
can run, but the function
user has set is ineffective.
1. The cable of the room
temperature sensor is connected
loosely;
2. The room temperature sensor
fails;
3. The sampling circuit is abnormal.
1.The cable of the coil temperature
sensor of the evaporator fails;
2.The coil temperature sensor of
the evaporator fails;
3.The sampling circuit is abnormal.
1. The wired controller and the
indoor control board are
connected loosely.
2. The sequence of the wiring
between the wired controller
to the indoor control board is
wrong;
3. The wiring between the
wired controller to the indoor
control board fails;
4. The wired controller is fails;
5. The indoor control board
is abnormal.
1.The wiring between the display
board to the indoor control
board is connected loosely;
2.The sequence of the wiring
between the display board to the
indoor control board is wrong;
3.The wiring between the display
board to the indoor control
board fails;
4.The display board fails;
5.The indoor control board fails.
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How to deal with
Replace EE data in MCU.
1. Reconnect the cable of the
room temperature sensor;
2. Replace the room temperature
sensor;
3. Replace the indoor control
board.
1. Reconnect the cable of the
coil temperature sensor of the
evaporator;
2. Replace the coil
temperature sensor of the
evaporator;
3. Replace the indoor
control board.
1. Reconnect the wiring between
the wired controller to the
indoor control board;
2. Replace the wiring between
the wired controller to the
indoor control board;
3. Replace the wiring between
the wired controller to the
indoor control board;
4. Replace the wired controller;
5. Replace the indoor control
board.
1. Reconnect the wiring
between the display board
to the indoor control board;
2. Replace the wiring between
the display board to the
indoor control board;
3. Replace the wiring between
the display board to the
indoor control board;
4. Replace the display board;
5. Replace the indoor control
board.
Remarks