Carrier 42QHC009DS Service Manual page 32

9.2.2 Indoor / outdoor unit's communication diagnosis and solution(E1)
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
Replace the reactor
Replace the reactor
E1
Indoor unit does not receive the feedback from 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
Power off, then restart the unit 2 minutes later
Yes
Measure Vs, is it positive fluctuation?
Measure Vs, is it positive fluctuation?
(Vs is the voltage between S and N of
(Vs is the voltage between S and N of
outdoor unit. Red pan-S, Black pan-N)
outdoor unit. Red pan-S, Black pan-N)
Yes
Check the outdoor wiring connection
Check the outdoor wiring connection
Yes
Check whether reactor
Check whether reactor
No
is normal?
is normal?
Yes
Replace the outdoor main PCB.
Replace the outdoor main PCB.
Power on. Is the error
Power on. Is the error
extinguished?
extinguished?
No
Replace the indoor main PCB.
Replace the indoor main PCB.
Check the indoor wiring connection
Check the indoor wiring connection
Replace the indoor main PCB.
Replace the indoor main PCB.
Replace the outdoor main PCB.
Replace the outdoor main PCB.
30
No
Yes
Power on. Is the error
Power on. Is the error
extinguished?
extinguished?
No