Acson international A5MAC 210D, Technical Manual

47

S/N

Failure

Code

Symptom

Possible Cause

Solution

18

The LED indicator 

of the unit displays 

ER34 and the 

wired controller 

displays 34

System 2 suction 

temperature is too 

high (40°C)

1.   Four-way valve jammed.

Gently knock the sides of the four-way valve 

and restart the system. Should the alarm 

persist, replace the four-way valve.

2.   Incorrect coil operation of the four-way 

valve. 

Replace the coil.

3.   Compressor idle protection due to air 

discharge temperature is too high.

Refer to item 19 in the table.

19

The LED indicator 

of the unit displays 

ER35 and the 

wired controller 

displays 35

System 2 discharge 

temperature is too 

high

1.   Damaged fan motor (cooling). 

Check and troubleshoot accordingly.

Recover and recharge accordingly.

2.   Air circulation short circuited (cooling).

3.   Heat exchanger is dirty (cooling). 

4.   The electronic expansion valve is not 

opened as expected (heating). 

Check the electronic expansion valve and 

troubleshoot accordingly.

5.   Water temperature is too high.

Insufficient refrigerant or leakages.

Change the setting for return water temperature 

(to be performed by service personnel). 

6.   

7.   Incomplete defrosting.

Change the defrosting parameter to be 

performed by service personnel

20

The LED indicator 

of the unit displays 

ER36 and the 

wired controller 

displays 36

System 1 low 

pressure

1.   Poor heat exchanging performance 

(heating).

Check the outdoor unit and troubleshoot 

accordingly.

2.   Outdoor fan motor have abnormality 

(heating).

Check and troubleshoot accordingly.

Check for leakages. 

Recover and recharge if needed.

System is leaking refrigerant or 

insufficient.

3.   

4.   Low pressure input port faulty.

Replace the module.

5.   Low pressure sensor damaged.

Replace the pressure sensor.

21

The LED indicator 

of the unit displays 

ER37 and the 

wired controller 

displays 37

System 1 suction 

superheat is too low

1.   Low pressure or temperature sensor 

is faulty

Check and replace if needed.

2.   Electronic expansion valve control 

algorithm malfunctioned.

Update the module

22

The LED indicator 

of the unit displays 

ER38 and the 

wired controller 

displays 38

System 1 leaking 

refrigerant

1.   Low pressure sensor failed.

Check and replace the sensor if needed.

Recover and recharge accordingly.

2.   Insufficient refrigerant charged.

23

The LED indicator 

of the unit displays 

ER39 and the 

wired controller 

displays 39

System 2 leaking 

refrigerant

1.   Low pressure sensor failed.

Insufficient refrigerant charged.

Check and replace the sensor if needed.

Recover and recharge accordingly.

2.   

24

The LED indicator 

of the unit displays 

ER40 and the 

wired controller 

displays 40

System 1 discharge 

temperature sensor 

failed

1.   TH1 temperature sensor is loosen or 

broken off. 

Check the control module and ensure the 

sensor is securely connected.

2.   TH1 temperature sensor is shorted/ 

open.

Check whether the resistance of TH1 

sensor meets specification requirements/

replace if not.

3.   Detection circuit for the temperature 

sensor in the control module has 

malfunctioned. 

Replace the control module.

25

The LED indicator 

of the unit displays 

ER41 and the 

wired controller 

displays 41

System 2 discharge 

temperature sensor 

failed

1.   TH2 temperature sensor is loosen 

or broken off. 

Check the control module and replug the 

temperature sensor.

2.   TH2 temperature sensor is shorted/ 

open.

Check whether the resistance of TH1 

sensor meets specification requirements/

replace if not.

3.   Detection circuit for the temperature 

sensor in the control module has 

malfunctioned.

Replace the control module.