Troubleshooting
SiBE811001EB
239
CONVENI-PACK
8.4.51 Transmission Error between Indoor Units and Outdoor Units
Error Code
U4
Applicable
Models
All indoor models
LRYEQ16AY1
Method of Error
Detection
Check if the transmission between indoor unit and outdoor unit is correctly executed using
micro-computer.
Error Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Indoor to outdoor, outdoor to outdoor transmission wiring F1, F2 disconnection, short circuit
or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective outdoor unit PCB (A1P)
Defective indoor unit PCB