Fujitsu ASUH18LMAS Service Manual page 91

2-31. E: A5.X. Low pressure error (Outdoor unit)
Indoor unit
Indicator
outdoor unit
Outdoor unit main PCB
Detective actuator
Suction pressure sensor
Forecast of cause
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
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
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
information"
2-31. E: A5.↓. Low pressure error (Outdoor unit)
Operation indicator
Timer indicator
Economy indicator
Error code
on page 03-80.
Continuous flash
Refer to "Error code table (Outdoor unit)"
Protection stop by suction pressure ≥ 0.02 MPaG
continued 5 minutes repeats 5 times within 24 hours.
3-way valve not opened
Outdoor unit ambient temperature too low
Outdoor unit operation failure, foreign matter on heat
EEV defective, strainer clogged
Solenoid valve defective
Low pressure sensor characteristics defective
Insufficient refrigerant
Main PCB failure
"Service parts information"
"Service parts information"
- (03-49) -
10 time flash
5 time flash
E: A5
on page 03-4
exchanger
on page 03-
on page
"Service parts
2. Troubleshooting with error code