Indoor / Outdoor Unit’s Communication Diagnosis And Solution - Carrier 38MAQB12-1 Service Manual

DIAGNOSIS AND SOLUTION (CONT)
Indoor / outdoor unit's communication diagnosis and solution (E1)
Error Code
Malfunction Decision Conditions
Supposed Causes
Troubleshooting
Replace the reactor
E1
Indoor unit does not receive feedback from the outdoor unit during 110 seconds and this condition
happens four times continuously.
·Wiring mistake
·Indoor or outdoor PCB faulty
Power off, then restart the unit 2 minutes later
Yes
Measure Vs., is it a positive fluctuation?
(Vs represents the voltage S and N of the
outdoor unit. Red pan-S, Black pan-N)
Yes
Check the outdoor wiring connection
Yes Yes
Check whether the
No
reactor is normal
Yes
Replace the outdoor main PCB.
Power on. Is the error resolved?
No
Replace the indoor main PCB
Check the indoor wiring connection
Replace the indoor main PCB.
Power on. Is the error resolved?
Replace the outdoor main PCB.
30
No
Yes
No