Rheem Comfort Control2 Installer's Manual page 39

Display Code Diagnostic Description
71 No inducer control communication
77 No gas valve feedback
78 Servo control fault
79 No Gas Valve Feedback
80 Low Airflow
81 Return air sensor out of range
82 Supply air sensor out of range
83 Coil Temperature Sensor Fault
Outdoor Ambient Temperature
84 Sensor Fault
Please refer to equipment instructions for additional fault information.
SYSTEM FAULT CODES
Display Code
85
86
P
d1
d3
d4
d5
d6
d7
d8
Diagnostic Description
Freeze protection
Air Freeze protection
Compressor Protector Fault
No Shared Data
Insufficient Indoor CFM
Memory Card Invalid
Card Hardware Conflict
Blower Horsepower Conflict
Blower Manufacturer Conflict
Old Shared Data
Installer's Guide  39