Acson AC Error Codes and Troubleshooting

Ascon AC Maintenance Dubai

The code indication changes as shown below, and notifies with a long beep.

00: Normal

A1: Indoor Pcb Error

A3: Drain Pump Abnormal

A5: Antifreeze (Cooling)/Heat Exchanger Overheat (Heating)

A6: Indoor Fan Motor Abnormalah Electrical Air Cleaner Abnormal

C4: Indoor Heat Exchanger (1) Thermistor Short/open

C5: Indoor Heat Exchanger (2) Thermistor Short/open

C7: Louver Limit Switch Error

C9: Indoor Room Thermistor Short/open

E1: Outdoor Pcb Error

E3: High Pressure Protection

E4: Low Pressure Protection

E5: Compressor Motor Lock/Compressor Overloaded

E6: Compressor Start-up Error

E7: Outdoor Dc Fan Motor Lock

E8: Ac Input Over Current

E9: Exv Error 4 Way Valve Error

F3: Discharge Pipe Overheat

F6: Heat Exchanger Overheat

HO: Compressor Sensor System Error

H3: High Pressure Switch Error

H6: Compressor Feedback Detection Error

H7: Fan Motor Overloaded/Over current/Sensor Abnormal

H8: AC Current Sensor Error

Error Code Faulty Indication Error / Code Faulty Indication

E01: Require manual reset (possible causes)

E02: Compressor 1 high temperature (overload)

E03: Compressor 2 high temperature (overload)

E04: Compressor 3 high temperature (overload)

E05: Compressor 4 high temperature (overload)

E06: Compressor 1 high pressure trip / contact open

E07: Compressor 2 high pressure trip / contact open

E08: Compressor 3 high pressure trip / contact open

E09: Compressor 4 high pressure trip / contact open

E10: Compressor 1 trip/low refrigerant/outdoor abnormal

E11: Compressor 2 trip/low refrigerant/outdoor abnormal

E12: Compressor 3 trip/low refrigerant/outdoor abnormal

E13: Compressor 4 trip/low refrigerant/outdoor abnormal

E14: Room sensor short E32 Compressor 1 de-ice

E15: Room sensor open E33 Compressor 2 de-ice

E16: Indoor coil sensor 1 short E34 Compressor 3 de-ice

E17: Indoor coil sensor 2 short E35 Compressor 4 de-ice

E18: Indoor coil sensor 3 short

E19: Indoor coil sensor 4 short

E20: Indoor coil sensor 1 open

E21: Indoor coil sensor 2 open

E22: Indoor coil sensor 3 open

E23: Indoor coil sensor 4 open

E24: Outdoor coil sensor 1 short

E25: Outdoor coil sensor 2 short

E26: Outdoor coil sensor 3 short

E27: Outdoor coil sensor 4 short

E28: Outdoor coil sensor 1 open

E29: Outdoor coil sensor 2 open

E30: Outdoor coil sensor 3 open

E31: Outdoor coil sensor 4 open

E32: Compressor 1 de-ice

E33: Compressor 2 de-ice

E34: Compressor 3 de-ice

E35: Compressor 4 de-ice

Error Diagnosis by Wired Controller (MC301) Item Code Description

E0: System malfunction

E1: Sensor Broken (TH1 discharge Temp.)

E2: Sensor Broken (TH2 inlet coil 1#)

E3: Sensor Broken (TH3 mid coil 1#)

E4: Sensor Broken (TH4 inlet coil 2#)

E5: Sensor Broken (TH5 mid coil 2#)

E6: Sensor Broken (TH6 inlet coil 3#)

E7: Sensor Broken (TH7 mid coil 3#)

E8: Sensor Broken (TH8 ambient temp)

E9: Sensor Broken (TH9 outlet coil)

EA: Sensor Broken (TH10 subcool outlet)

EB: Sensor Broken (TH11 subcool suction)

EC: Sensor Broken (TH12 suction)

EF: Emergency Run

F0: Outdoor Storage Malfunction

F1: Sensor Broken (indoor inlet coil)

F2: Sensor Broken (indoor mid coil)

Error Diagnosis by Wired Controller (MC301) Item Code Description

F3: Sensor Broken (indoor outlet coil)

F4: Sensor Broken (indoor return air)

F5: Sensor Broken (indoor supply air

F6: Indoor and controller communication malfunction

F7: Ambient temp exceed the limit

F8: 4WV malfunction

F9: Refrigerant leakage

FA: Controller storage malfunction

FB: Water Pump (indoor water pump)

FC: Indoor and outdoor communication malfunction

FE: Master and slave communication malfunction

H0: Digital comp overload

H1: Fixed Comp1 overload

H2: Fixed Comp2 overload

H3: Fixed Comp3 overload

H4: High pressure too high

H5: Sensor broken, high pressure

H6: Discharge temp too high

L0: Super heat too low

L1: Low pressure too low

L2: Sensor broken, low pressure

10: System malfunction

11: Sensor broken (slave TH1 discharge temp)

12: Sensor broken (slave TH2 inlet coil 1#)

13: Sensor Broken (slave TH3 mid coil 1#)

14: Sensor broken (slave TH4 inlet coil 2#)

15: Sensor broken (slave TH5 mid coil 2#)

16: Sensor broken (slave TH6 inlet coil 3#)

17: Sensor broken (slave TH7 mid coil 3#)

18: Sensor broken (slave TH8 ambient temp)

19: Sensor broken (slave TH9 outlet coil)

1A: Sensor broken (slave TH10 subcool outlet)

1B: Sensor broken (slave TH11 subcool suction)

1C: Sensor Broken (slave TH12 suction)

1F: Emergency run (slave)

20: Outdoor storage (slave)

27: Ambient temp exceed the limit (slave)

28: 4WV malfunction (slave)

29: Refrigerant leakage (slave)

30: Digital comp overload (slave)

31: Fixed comp1 overload (slave)

32: Fixed comp2 overload (slave)

33: Fixed comp 3 overload (slave)

34: High pressure too high (slave)

35: Sensor broken, high pressure (slave)

36: Discharge temp too high (slave)

40: Super heat too low (slave)

41: Low pressure too low (slave)

42: Sensor broken, low pressure (slave)

A1: Indoor PCB error

A3: Drain pump fault

A5: Antifreeze (Cooling) / Heat exchanger overheat(Heating)

A6: Indoor fan motor fault

AH: Electrical air cleaner fault

C4: Indoor heat exchanger (1) thermistor short/open

C5: Indoor heat exchanger (2) thermistor short/open

C7: Louver limit switch error

C9: Indoor room thermistor short/open

E1: Outdoor PCB error

E3: High pressure protection

E4: Low pressure protection

E5: Compressor motor lock/compressor overloaded

E6: Compressor start-up error

E7: Outdoor DC fan motor lock

E8: Ac input over current

E9: EXV error

EA: 4 way valve error

F3: Discharge pipe overheat

F6: Heat exchanger overheat

HO: Compressor sensor system error

H3: High pressure switch error

H6: Compressor feedback detection error

H7: Fan motor overloaded/over current/sensor fault

H8: AC current sensor error

H9: Outdoor air thermistor short/open

J1: Pressure sensor error

J3: Compressor discharge pipe thermistor short/open/misplaced

J5: Suction pipe thermistor short/open

J6: Outdoor heat exchanger thermistor short/open

J7: Sub cooling heat exchanger thermistor short/open

J8: Liquid pipe thermistor short/open

J9: Gas pipe thermistor short/open

L1: Inverter outdoor PCB error

L3: Outdoor control box overheat

L4: Heat sink overheat

L5: IPM error/IGBT error

L8: Electrical thermal switch

L9: Stall prevention

LC: Communication error (outdoor PCB & inverter PCB)

P1: Open phase or voltage unbalance

P4: Heat sink thermistor short/open

PJ: Capacity setting error

U0: Insufficient gas

U2: DC voltage out of range

U4: Communication error

U7: Communication error (outdoor PCB & IPM PCB)

UA: Installation error

UF: Piping & wiring installation mismatch/wrong wiring/insufficient gas

UH: Anti freeze (other rooms)


If any malfunction of the air conditioner unit is noted, immediately switch off the power supply to the unit. Check the following fault conditions and causes for some simple troubleshooting tips.

Fault: The compressor does not operate 3 minutes after the air conditioner unit is started.

Causes / Action: -Protection against frequent starting. Wait for 3 to 4 minutes for the compressor to start operating.

Fault: The air conditioner unit does not operate.

Causes / Action:

– Power failure, or the fuse needs to be replaced.
– The power plug is disconnected.
– It is possible that your delay timer has been set incorrectly.
– If the fault persist after all these verifications, please contact the air conditioner unit installer.

Fault: The air flow is too low

Causes / Action:

– The air filter is dirty.
– The doors or windows are open.
– The air suction and discharge are clogged.
– The regulated temperature is not high enough

Fault: Discharge air flow has bad odour.

Causes / Action:

– Odours may be caused by cigarettes, smoke particles, perfume etc. which might have adhered onto the coil.

Fault: Condensation on the front air grille of the indoor unit.

Causes / Action:

– This is caused by air humidity after an extended long period of operation.
– The set temperature is too low, increase the temperature setting and operate the unit at high fan speed.

Fault: Water flowing out from the air conditioner unit.

Causes / Action: – Switch off unit and call dealer

Fault: Hissing air flow sound from the air conditioner unit during operation.

Causes / Action: – Refrigerant fluid flowing into the evaporator coil

If the fault persists, please call Ac Maintenance Dubai

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