Fujitsu AOUH18LMAS1, Service Manual

Page: 91 / 215

2-31. E: A5.X. Low pressure error (Outdoor unit)
Indicator
Indoor unit
Operation indicator 10 time flash
Timer indicator 5 time flash
Economy indicator Continuous flash
Error code E: A5
outdoor unit Refer to "Error code table (Outdoor unit)" on page 03-4
Detective actuator Outdoor unit main PCB
Protection stop by suction pressure ≥ 0.02 MPaG
continued 5 minutes repeats 5 times within 24 hours.
Suction pressure sensor
Forecast of cause
3-way valve not opened
Outdoor unit ambient temperature too low
Outdoor unit operation failure, foreign matter on heat
exchanger
EEV defective, strainer clogged
Solenoid valve defective
Low pressure sensor characteristics defective
Insufficient refrigerant
Main PCB failure
Check point 1. Check if 3-way valve is open
If the 3-way valve is closed, open the 3-way valve and check operation.
NOTE: For cooling operation, check gas side of the 3-way valve.
For heating operation, check liquid side of the 3-way valve.
Check point 2. Check the outdoor unit ambient temperature (Only when heating operation)
Outdoor unit ambient temperature lower than operating range?
Check point 3. Check the outdoor unit fan and heat exchanger (Only when heating operation)
• No foreign object in air passage?
• Heat exchanger fins clogged?
• Fan rotes?
• Check the motor. (Refer to outdoor unit fan motor in "Service parts information" on page 03-
80.)
Check point 4. Check the electronic expansion valve (EEV) and strainer
• Check if EEV open.
Refer to outdoor unit Electronic Expansion Valve (EEV) in "Service parts information" on page
03-80.
• Check the strainer clogging.
Check point 5. Check the suction pressure sensor
Check the suction pressure sensor characteristics.
NOTE: For the characteristics of the thermistor, refer to suction pressure sensor in "Service parts
information" on page 03-80.
2-31. E: A5.↓. Low pressure error (Outdoor unit)
- (03-49) -
2. Troubleshooting with error code
TR
O
U
B
LESH
O
O
TI
N
G
TR
O
U
B
LESH
O
O
TI
N
G