Rheem RHMV2421MNACJA Service Manual page 55

2. TROUBLESHOOTING WITH ERROR CODE
Troubleshooting 1
Serial communication error
(Serial reverse transfer error)
Detective actuators:
Outdoor unit main PCB
Outdoor unit fan motor
Detective details:
When indoor unit cannot receive serial signal
from Outdoor unit more than 2minutes
after power ON, or the indoor unit cannot
receive serial signal more than 15 seconds
during normal operation.
Forecast of cause:
1. Connection failure
2. External cause
3. Main PCB failure
4. Active filter module failure
5. Transistor PCB (IPM) failure
6. Filter PCB failure
7. Outdoor unit fan motor failure
Check Point 1-1 : Reset power and operate
Does error indication reappear?
YES YES
Check Point 2 : Check connection
Check any loose or removed connection line of
between indoor unit and outdoor unit.
>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.
Check connection condition in control unit.
(If there is loose connector, open cable or mis-wiring)
OK
next page
Indicate or Display:
Indoor unit
Operation lamp: 1 time Flash,
Timer lamp
Wired remote control
Error code : [E : 11]
Outdoor unit (RP1736/1748HJVXA)
No indication
NO
Check Point 1-2 : Check external cause such as noise
Check if ground connection is proper.
Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).
03-05
: 1 time Flash