Midea CTBU-09HWFN1-M Service Manual page 97

16.3.2 Communication malfunction between indoor and outdoor units diagnosis and solution
(E1)
For 9K-24K:
Error Code
Malfunction conditions
Potential causes
Trouble shooting:
Replace the reactor
Replace the reactor
E1
If the indoor unit does not receive feedback from outdoor unit for
110 seconds 4 consecutive times.
Wiring mistake
●
Faulty indoor or outdoor PCB
●
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 3 and 2 of
(Vs is the voltage between 3 and 2 of
outdoor unit. Red pan-3, Black pan-2)
outdoor unit. Red pan-3, Black pan-2)
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.
94
No
Yes
Power on. Is the error
Power on. Is the error
extinguished?
extinguished?
No