Lennox Split AC Error Codes

Lennox Split AC Error Codes

If there is an error occurring during the operation of the system, the error code will be displayed on the LCD, as show in Fig.5.1. If multi errors occur at the same time, their codes will be displayed circularly. Note: In event of any error, please turn off the unit and contact the professionally skilled personnel.
Meaning of Each Error
Return air temperature sensor open/ short circuited F1
Drive board communication error P6
Evaporator temperature sensor open/ short circuited F2
Compressor overheating protection H3
Indoor unit liquid valve temperature sensor open/short circuited b5
Indoor and outdoor units unmatched LP
Indoor gas valve temperature sensor open/ short circuited b7
Communication line misconnected or expansion valve error dn
IPM temperature sensor open/short circuited P7
Running mode conflict E7
Outdoor ambient temperature sensor open/ short circuited F3
Pump-down Fo
Outdoor unit condenser mid-tube temperature sensor open/short circuited F4
Jumper error C5
Discharge temperature sensor open/ short circuited F5
Forced defrosting H1
Indoor and outdoor communication error E6
Compressor startup failure Lc
DC bus under-voltage protection PL
High discharge temperature protection E4

DC bus over-voltage protection PH
Overload protection E8
Compressor phase current sensing circuit error U1
Whole unit over-current protection E5
Compressor demagnetization protection HE
Over phase current protection P5
PFC protection Hc
Compressor desynchronizing H7
IPM Temperature Protection P8
IPM Current protection H5
Over-power protection L9
Compressor phase loss/reversal protection Ld
System charge shortage or blockage protection F0
Frequency restricted/reduced with whole unit current protection F8
Capacitor charging error PU
Frequency restricted/reduced with IPM
Current protection En
High pressure protection E1
Frequency restricted/reduced with high discharge temperature F9
Low pressure protection E3
Frequency restricted/reduced with antifreezing protection FH
Compressor stalling LE
Frequency restricted/reduced with overload protection F6
Over-speeding LF
Frequency restricted/reduced with IPM temperature protection EU
Drive board temperature sensor error PF
Indoor unit full water error E9
AC contactor protection P9
Anti-freezing protection E2
Temperature drift protection PE
AC input voltage abnormal PP
Sensor connection protection Pd
Whole unit current sensing circuit error U5
DC bus voltage drop error U3
4-way valve reversing error U7
Outdoor fan 1 error protection L3
Motor stalling H6
Outdoor fan 2 error protection LA
PG motor zero-crossing protection U8