Lennox LIUH018021T431E-1 Service Manual page 122

2.1.5 Icon explanation on indoor display board (Compact cassette).
2.2 Indoor Unit Malfunctions
Floor Standing
For
Indoor EEPROM malfunction
Communication malfunction between indoor and outdoor units
Indoor fan speed malfunction
T1 temperature sensor open or short circuit
T2 temperature sensor open or short circuit
Refrigerant leakage detection
Outdoor unit is faulty (for old communication protocol)
Overcurrent protection (for some units)
T4 temperature sensor open or short circuit
T3 temperature sensor open or short circuit
T5 temperature sensor open or short circuit
Outdoor EEPROM malfunction (for some units)
Outdoor fan speed malfunction
T2B temperature open or short circuit
IPM module malfunction
DC voltage too high/too low protection
High temperature protection of compressor top
Low ambient temperature protection
Inverter compressor drive protection
Outdoor IGBT sensor is faulty
For Other Types (18K-60K):
Indoor EEPROM malfunction
Communication malfunction between indoor and outdoor units
Indoor fan speed malfunction
T1 temperature sensor open or short circuit
T2 temperature sensor open or short circuit
Refrigerant leakage detection
Water level alarm malfunction
Communication error between master and slave unit (for twins system)
Another indoor unit malfunction (for twins system)
Outdoor unit is faulty (for old communication protocol)
Overcurrent protection (for some units)
T4 temperature sensor open or short circuit
Electrical Control System
:
Malfunction
Malfunction
Error Code
E0
E1
E3
E4
E5
EC
Ed
F0
F1
F2
F3
F4
F5
F6
P0
P1
P2
P3
P4
P7
Error Code Timer Lamp
E0 X
E1 X
E3 X
E4 X
E5 X
EC X
EE X
E8 X
E9 X
Ed X
F0 O
F1 O
Troubleshooting
Operation Lamp
(flashes)
1
2
4
5
6
7
8
9
10
11
1
2
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