SiUS371614E
Troubleshooting by Error Code
Service Diagnosis
252
3.56 Transmission Error between Indoor Units and Outdoor
Units
Error Code
U4
Applicable
Models
All indoor unit models
All outdoor unit models
Method of Error
Detection
Microcomputer checks if transmission between indoor and outdoor units is normal.
Error Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Short circuit in indoor-outdoor or outdoor-outdoor transmission wiring (F1 / F2), or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective indoor unit PCB
Defective outdoor unit PCB
Summary of Contents for REYQ-TA Series
Page 1: ...Service Manual SiUS371614E REYQ72 456TAYDU REYQ72 456TATJU Heat Recovery 60 Hz...
Page 304: ...Wiring Diagrams SiUS371614E 291 Appendix REYQ96 120TAYDU 2D106425A...
Page 305: ...SiUS371614E Wiring Diagrams Appendix 292 REYQ144 168TAYDU 2D106426A...
Page 306: ...Wiring Diagrams SiUS371614E 293 Appendix REYQ72TATJU 3D106421A...
Page 307: ...SiUS371614E Wiring Diagrams Appendix 294 REYQ96 120TATJU 2D106422A...
Page 308: ...Wiring Diagrams SiUS371614E 295 Appendix REYQ144 168TATJU 2D106423A...
Page 318: ...Wiring Diagrams SiUS371614E 305 Appendix VAM1200GVJU 3D073270C...
Page 320: ...Wiring Diagrams SiUS371614E 307 Appendix 1 4 2 Multi Branch Selector Unit BS4Q54TVJ 3D089123B...
Page 321: ...SiUS371614E Wiring Diagrams Appendix 308 BS6 8Q54TVJ 2D089122B...
Page 322: ...Wiring Diagrams SiUS371614E 309 Appendix BS10 12Q54TVJ 2D089121B...
Page 323: ...Revision History Month Year Version Revised contents 02 2017 SiUS371614E First edition...