Diagnostic Codes - Gree Multi21 Series Owner's Manual

DIAGNOSTIC CODES

Troubleshooting
The unit has onboard diagnostics. The outdoor unit will provide status indicators. The indoor
wall unit and remote controller will display error codes. The following is a summary of the
codes with explanation:
Malfunction Name
Liquid Valve Coil Temperature
Sensor Malfunction
Gas valve temperature sensor
is open/short circuited
System Configuration
Malfunction
Wrong connection of communication
wire or malfunction of electronic
expansion valve
System High Pressure
Indoor Anti-Freeze Protection
Low Pressure Protection
Compressor High Discharge
Temperature Protection
Overcurrent Protection
Communication Malfunction
Mode conflict (Indoor units
calling for simultaneously
Heating and Cooling)
Indoor Unit
Outdoor Unit Indicators
& Remote
Yellow
Display
b5
b7
C5
dn
E1
E2 3 flashes
and 1 sec Off
E3
and 1 sec Off
E4 7 flashes
and 1 sec Off
E5
5 flashes
and 1 sec Off
E6 Continuous
On
E7
Possible Causes
Red
1) Loose or bad connection between sensor and control board
2) Liquid valve temperature sensor damaged
3) Control board malfunction
Hardware malfunction
1) No jumper cap inserted on the control board
2) Incorrect or damaged jumper cap on control board
3) Indoor and outdoor units are not compatible
Hardware malfunction
1) Over charged with refrigerant
2) Blocked or dirty outdoor coil
3) Extreme outdoor ambient conditions
1) Low return airflow
2) Indoor fan speed is too low
3) Indoor coil is blocked or dirty
9 flashes 1) Low on refrigerant
2) Pressure sensor is damaged
Please refer to the malfunction analysis (discharge
temperature, overload) in service manual
1) Supply voltage is unstable
2) Supply voltage is too low and system load is too high
3) Indoor coil is blocked or dirty
1) Communication cable is mis-wired between indoor
and outdoor units
2) Indoor or Outdoor control board malfunction
Operation status
20