View source for Multi Plus ODU Main Board Troubleshooting

{| class="wikitable"
! Fault Code
! Fault Description
! Possible Reason for Fault
! Potential Fixes
|-
| 1
| Outdoor Ambient Temperature Sensor Fault
| 
* The outdoor ambient temperature sensor connection is loose
* The outdoor ambient temperature sensor has failed
* The sampling circuit has failed
|
* Reconnect the outdoor ambient temperature sensor
* Replace the outdoor ambient temperature sensor
* Replace the outdoor board
|-
| 2
| Outdoor Coil Temperature Sensor Fault
| 
* The outdoor coil temperature sensor connection is loose
* The outdoor coil temperature sensor has failed
* The sampling circuit has failed
|
* Reconnect the outdoor coil temperature sensor
* Replace the outdoor coil temperature sensor
* Replace the outdoor board
|-
| 3
| The Unit Over-Current Turn Off Fault
|
* Control board current sampling circuit has failed 
* The current is too high because the supply voltage is too low
* The compressor is blocked
* Overload in heating mode
* Overload in cooling mode
| 
* Replace the control board
* Replace the compressor
|-
| 4
| EEprom Data Error
| 
* EE components have failed
* EE components control circuit failed
* EE components have been inserted incorrectly
| 
* Replace the EE components
* Replace the outdoor control board
* Reassemble the EE components
|-
| 5
| Cooling Freezing
Protection (the indoor
coil temperature is too
low) or Heating
Overload (indoor coil
temperature is too
high)
| 
* The indoor unit isn't blowing air normally
* The room temperature is too low in cooling mode or the room temperature is too high in heating
* Air filter is dirty
* The duct resistance is too high to result in low air flow
* The setting fan speed is too low
* The indoor unit is not standard installed, air inlet is too near with air outlet
|
* Check the indoor fan, indoor fan motor and evaporator
* Clean the filter
* Check the volume control valve, duct length etc.
* Set the speed with high speed
* Reinstall the indoor unit refer to the user manual to change the distance between the indoor unit and the wall or ceiling.
|-
| 7
| Communication fault between the indoor unit and outdoor unit
|
* The connection between the indoor unit and
outdoor unit is poor
* The communication cable is loose
* The communication cable is faulty
* The indoor control board is faulty
* The outdoor control board is faulty
* Communication circuit fuse is open
* The specification of communication cable is incorrect
| 
* Reconnect the connection cable by referring to the wiring diagram
* Reconnect the communication cable
* Replace the communication cable
* Replace the indoor control board
* Replace the outdoor control board
* Check the communication circuit, adjust the DIP switch and the short-circuit fuse
* Choose suitable communication cable by referring to the user manual
|-
| 13
| Compressor overheat protector device
| 
* The wiring of the overload protector connection is loose
* The overload protector has failed
* Insufficient refrigerant
* The copper pipping is longer than normal, but no additional refrigerant has been added
* The expansion valve has failed
* The outdoor control board has failed
|
* Reconnect the wiring of the
overload protector
* Replace the overload
protector
* Check for a refrigerant leak, fix it and re-add refrigerant
* If there is no leak, add refrigerant according to the length of the copper tubing.
* Replace expansion valve
* Replace the outdoor control
board
|-
| 14
| The high pressure switch operates or the unit turns off for high pressure protection
| 
* The wiring of the high pressure protector connection is loose;
* The high pressure protector has failed
* The outdoor control board is abnormal
* Overload in cooling
* Overload in heating
|
* Reconnect the high pressure protector
* Replace the high pressure protector
* Replace the outdoor control board
* Refer to "Overload in Cooling Mode addendum"
* Refer to "Overload in Heating Mode addendum"
|-
| 15
| Low pressure switch protection or the unit turned off for low pressure protection
|
* The wiring of the low pressure switch is loose
* The low pressure switch has failed
* Insufficient amount of refrigerant
* Expansion valve failure in heating mode
* The outdoor control board is abnormal
|
* Reconnect the wiring of the low pressure switch
* Replace the low pressure switch
* Check for a refrigerant leak, fix it and re-add refrigerant
* Replace the expansion valve;
* Replace the outdoor control
board
|-
| 16 
| Overload protection in cooling mode
| System Overload
| Refer to "Overload in Cooling Mode addendum"
|-
| 17
| Discharge temperature sensor fault
| 
* The wiring of the discharge temperature sensor connection is loose
* The discharge temperature sensor has failed
* The sampling circuit is abnormal
|
* Reconnect the discharge temperature sensor
* Replace the discharge temperature sensor
* Replace the outdoor control board.
|-
| 18
| AC voltage is abnormal
| 
* The AC voltage > 275V or < 160V
* The AC voltage of sampling circuit on the driver board is abnormal
|
* Please check the power supply
* Replace the driver board
|-
| 19
| Suction temperature sensor fault
| 
* The wiring of the suction temperature sensor connection is loose
* The suction temperature sensor has failed
* The sampling circuit is abnormal
|
* Reconnect the suction temperature sensor
* Replace the suction temperature sensor
* Replace the outdoor control board
|-
| 22
| Defrosting sensor fault
| 
* The wiring of the defrosting sensor connection is loose
* The defrosting sensor has failed
* The sampling circuit is abnormal
|
* Reconnect the defrosting sensor
* Replace the defrosting sensor
* Replace the outdoor control board
|-
| 23
| Expansion valve A tube (thin) sensor fault
| 
* The wiring of the sensor for the expansion valve A(thin tube) connection is loose
* The sensor for the expansion A(thin tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve A (thin tube)
* Replace the sensor for the expansion valve A (thin tube)
* Replace the outdoor control board
|-
| 24
| Expansion valve B tube (thin) sensor fault
| 
* The wiring of the sensor for the expansion valve B(thin tube) connection is loose
* The sensor for the expansion B(thin tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve B (thin tube)
* Replace the sensor for the expansion valve B (thin tube)
* Replace the outdoor control board
|-
| 25
| Expansion valve C tube (thin) sensor fault
| 
* The wiring of the sensor for the expansion valve C(thin tube) connection is loose
* The sensor for the expansion C(thin tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve C (thin tube)
* Replace the sensor for the expansion valve C (thin tube)
* Replace the outdoor control board
|-
| 26
| Expansion valve D tube (thin) sensor fault
| 
* The wiring of the sensor for the expansion valve D(thin tube) connection is loose
* The sensor for the expansion D(thin tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve D (thin tube)
* Replace the sensor for the expansion valve D (thin tube)
* Replace the outdoor control board
|-
| 27
| Expansion valve A tube (thick) sensor fault
| 
* The wiring of the sensor for the expansion valve A(thick tube) connection is loose
* The sensor for the expansion A(thick tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve A (thick tube)
* Replace the sensor for the expansion valve A (thick tube)
* Replace the outdoor control board
|-
| 28
| Expansion valve B tube (thick) sensor fault
| 
* The wiring of the sensor for the expansion valve B(thick tube) connection is loose
* The sensor for the expansion B(thick tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve B (thick tube)
* Replace the sensor for the expansion valve B (thick tube)
* Replace the outdoor control board
|-
| 29
| Expansion valve C tube (thick) sensor fault
| 
* The wiring of the sensor for the expansion valve C(thick tube) connection is loose
* The sensor for the expansion C(thick tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve C (thick tube)
* Replace the sensor for the expansion valve C (thick tube)
* Replace the outdoor control board
|-
| 30
| Expansion valve D tube (thick) sensor fault
| 
* The wiring of the sensor for the expansion valve D(thick tube) connection is loose
* The sensor for the expansion D(thick tube) has failed
* The sampling circuit is abnormal
|
* Reconnect the sensor for the expansion valve D (thick tube)
* Replace the sensor for the expansion valve D (thick tube)
* Replace the outdoor control board
|-
| 45
| IPM fault
| Please refer to "drive board fault codes" for more information
| Please refer to "drive board fault codes" for more information
|-
| 46
| IPM and control board communication fault
| 
* The cable between the control board and the driver board is loose
* The cable between the control board and the driver board has failed
* The driver board has failed
* The control board has failed
| 
* Reconnect the cable between the control board and the driver board
* Replace the communication cable between the control board and the driver board
* Replace the driver board
* Replace the control board
|-
| 47
| Discharge temperature too high fault
| 
* Insufficient amount of refrigerant 
* The refrigerant of the unit is not enough due to additional length of the installation pipe
* Throttling service has failed
* The outdoor ambient temperature is too high
|
* Check for refrigerant leaks. Fix leak and re-add refrigerant
* Add refrigerant according to additional installation pipe length
* Replace the throttling service (such as capillary, expansion valve)
|-
| 48
| Outdoor DC fan motor fault (upper fan motor)
|
* The wiring of the upper DC fan motor is loose
* The cord of the upper DC fan motor has failed
* The upper DC fan motor has failed
* The drive circuit of the upper DC fan motor has failed
* The outdoor fan has been blocked
|
* Reconnect the wiring of the upper DC fan motor
* Replace the upper DC fan motor
* Replace the driver board of the fan motor
* Check the outdoor fan and ensure the outdoor fan can run normally
|-
| 49
| Outdoor DC fan motor fault (lower fan motor)
|
* The wiring of the lower DC fan motor is loose
* The cord of the lower DC fan motor has failed
* The lower DC fan motor has failed
* The drive circuit of the lower DC fan motor has failed
* The outdoor fan has been blocked
|
* Reconnect the wiring of the lower DC fan motor
* Replace the lower DC fan motor
* Replace the driver board of the fan motor
* Check the outdoor fan and ensure the outdoor fan can run normally
|-
| 91
| The unit turned off due to the IPM board over heating fault
| 
* The outdoor ambient temperature is too high
* The speed of the outdoor fan motor is too low
* The outdoor unit has been installed incorrectly
* The supply power is too low
|
* Check the fan capacitor, and replace the fan capacitor if it has failed
* Reinstall the outdoor unit by referring to the installation user manual
|-
| 96
| The refrigerant of the unit is not enough fault
| Insufficient amount of refrigerant
| 
* Check for leaks
* Charge refrigerant to recommended levels
|-
| 97
| 4-way valve communication failure fault
| 
* The wiring of the 4-way valve coil is loose
* The 4-way valve coil has failed
* The 4-way valve has failed
* The driver board of the 4-way valve has failed
|
* Reconnect the wiring of the 4-way valve
* Replace the 4-way valve coil
* Replace the 4-way valve
* Replace the driver board of the 4-way valve
|}
{| class="wikitable"
! colspan="3" | Overload in Cooling Mode Addendum
|-
! Number
! Cause
! Corrective Measures
|-
| 1
| Too much refrigerant
| Discharge refrigerant and refill to the appropriate level
|-
| 2 
| The outdoor ambient temperature is too high
| Please use within the rated ambient temperature range
|-
| 3
| The air outlet and the air inlet of the outdoor unit has short circuited
| Adjust the installation according to the installation manual
|-
| 4
| The outdoor heat exchanger is dirty
| Clean the heat exchanger of the outdoor unit
|-
| 5
| The speed of the outdoor fan motor is too low
| Check the outdoor fan motor or fan capacitor
|-
| 6
| The outdoor fan is broken or the outdoor fan is blocked
| Check the outdoor fan
|-
| 7
| The air inlet and outlet and been blocked
| Remove the blockage
|-
| 8
| The expansion valve or the capillary has failed
| Replace the expansion valve or the capillary
|-
|}
{| class="wikitable"
! colspan="3" | Overload in Heating Mode Addendum
|-
! Number
! Cause
! Corrective Measures
|-
| 1
| Too much refrigerant
| Discharge refrigerant and refill to the appropriate level
|-
| 2 
| The indoor ambient temperature is too high
| Please use within the rated ambient temperature range
|-
| 3
| The air outlet and the air inlet of the indoor unit has short circuited
| Adjust the installation according to the installation manual
|-
| 4
| The indoor filter is dirty
| Clean the indoor filter
|-
| 5
| The speed of the indoor fan motor is too low
| Check the indoor fan motor or fan capacitor
|-
| 6
| The indoor fan is broken or the outdoor fan is blocked
| Check the indoor fan
|-
| 7
| The air inlet and outlet and been blocked
| Remove the blockage
|-
| 8
| The expansion valve or the capillary has failed
| Replace the expansion valve or the capillary
|-
|}
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