Service manual

Error Codes: System Malfunctions ESIE03–01
3–62 Part 3 – Troubleshooting
3
1
3
4
5
4.2 Gas Shortage Detection (UO)
Error code U0
Error method The discharge pipe thermistor detects the malfunction temperature at which there can be a gas
shortage. If the discharge temperature exceeds 125°C during more than 20 s, the outdoor unit will stop
and retry when the guard timer is OFF (3 min have passed).
During the retrial, the expansion valve will be opened 90 pulses more than in case of the previous start.
When the unit restarts with a fully opened expansion valve, the remote controller displays “U0” after
pressing the test button.
Error generation The error is generated when the microcomputer detects gas shortage. However, the unit can still
operate.
Causes The possible causes are:
P Refrigerant shortage
P Clogging of the refrigerant piping circuit.
Troubleshooting To troubleshoot, proceed as follows:
Caution Be sure to turn off power switch before connecting or disconnecting the connector, or parts damage
may occur.
Check the amount of
refrigerant.
NoIs it correct?
Fill with the proper
amount of refrigerant.
Check the refrigerant piping
circuit for clogging.
Check the expansion valve.
Refer to error E9.
Check the discharge thermistor.
Refer to error F3.
Yes