Troubleshooting - Haier AU55NFIAIA Service Manual

10.3 Troubleshooting

(1) Indoor unit trouble indication: timer indicator flashes (once, twice, 3 times, 7 times)
Abnormal reasons:
Heat sensitive resister is short circuit or open circuit
The treatment to sensor output part in PC board is improper, such as poor contact of
package part, the electrolytic capacitor for filtering is failed, etc.
Treatment:
Remove the heat sensitive resister, test and measure its numerical value. According to the
resister temperature character table to evaluate if it is heat sensitive resister abnormal. If
numerical value of resister is normal, check if it is poor contact. If contact is good, replace the
indoor unit PC board.
(2) Outdoor unit trouble indication: timer indicator flashes (4 times)
Abnormal reasons:
Communication wire is open circuit or short circuit
There is powerful electromagnetic disturbing source near the air conditioner
The indoor & outdoor unit are not correctly set with unit number
The PC board is improper
Treatments: use the ohm grade of multimeter to check the numerical value of resister between
communication wire to determine if it is short circuit or open circuit. If normal, examine if
there is powerful electromagnetic disturbing source near the air conditioner, such as radio
wave sending devices. After verifying there is no powerful disturbance near air conditioner,
reset the unit number of indoor unit and outdoor unit. If there is still abnormal, change the PC
board of the trouble indoor & outdoor unit. Please note that after changing the PC board of
indoor & outdoor unit, they both should be reset their unit number.
(2) Indoor unit trouble indication: timer indicator flashes (5 times)
Abnormal reasons:
Communication wire is open circuit or short circuit
There is powerful electromagnetic disturbing source near the air conditioner
PC board is improper
Treatments: use the ohm grade of multimeter to check the numerical value of resister between
communication wire to determine if it is short circuit or open circuit. If normal, examine if
there is powerful electromagnetic disturbing source near the air conditioner, such as radio
wave sending devices. After verifying there is no powerful disturbance near air conditioner,
change the PC board of abnormal indoor unit or electronic expansion valve driver.
(3) Indoor unit trouble indication: timer indicator flashes (6 times)
Abnormal reasons:
PC board is improper
Treatment: change the improper PC board of indoor unit.
(4) Indoor unit trouble indication: timer indicator flashes (8 times)
Abnormal reasons:
The PC board of electronic expansion valve driver is improper
Treatment: change the PC board of electronic expansion valve driver.
(5) Indoor unit trouble indication: timer indicator flashes (10 times)
Abnormal reasons:
Plastic sealed motor is improper
PC board is improper
Commercial Air Conditioner
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Model: AU55NFIAIA