Lennox AC Error Codes and Troubleshooting

 This manual is applicable only to the following models.

Lennox Air Conditioner Inverter Split Type Error Codes;

Lennox AC Error Codes and Troubleshooting

LNIV2610 LNIV3510 LNIV5010 LNIV6510

Indoor Unit Error Display:

Error Codes	Cause
E0	EEPROM parameter error
E1	Indoor/outdoor units communication protection
E2	Zero-crossing signal error
E3	Indoor fan speed out of control
E5	Open or short circuit of outdoor temperature sensor or outdoor unit EEPROM parameter error
E6	Open or short circuit of room or evaporator temperature sensor
E7	Outdoor fan speed out of control
P0	IBM malfunction or IGBT over-strong current protection
P1	Over voltage or too low voltage protection
P2	Temperature protection of compressor top
P4	Inverter compressor drive error

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.

Lennox Split AC Error Codes

Note: In event of any error, please turn off the unit and contact the professionally skilled personnel.

Meaning of Each Error

Error Codes	Meaning
F1	Return air temperature sensor open/ short circuited
P6	Drive board communication error
F2	Evaporator temperature sensor open/ short circuited
H3	Compressor overheating protection
b5	Indoor unit liquid valve temperature sensor open/short circuited
LP	Indoor and outdoor units unmatched
b7	Indoor gas valve temperature sensor open/ short circuited
dn	Communication line misconnected or expansion valve error
P7	IPM temperature sensor open/short circuited
E7	Running mode conflict
F3	Outdoor ambient temperature sensor open/ short circuited
Fo	Pump-down
F4	Outdoor unit condenser mid-tube temperature sensor open/short circuited
C5	Jumper error
F5	Discharge temperature sensor open/ short circuited
H1	Forced defrosting
E6	Indoor and outdoor communication error
Lc	Compressor startup failure
PL	DC bus under-voltage protection......
E4	High discharge temperature protection
PH	DC bus over-voltage protection
E8	Overload protection
U1	Compressor phase current sensing circuit error
E5	Whole unit over-current protection
HE	Compressor demagnetization protection
P5	Over phase current protection
Hc	PFC protection
H7	Compressor desynchronizing
P8	IPM Temperature Protection
H5	IPM Current protection
L9	Over-power protection
Ld	Compressor phase loss/reversal protection
F0	System charge shortage or blockage protection
F8	Frequency restricted/reduced with whole unit current protection
PU	Capacitor charging error
IPM	Frequency restricted/reduced with
En	Current protection
E1	High pressure protection
F9	Frequency restricted/reduced with high discharge temperature
E3	Low pressure protection
FH	Frequency restricted/reduced with antifreezing protection
LE	Compressor stalling
F6	Frequency restricted/reduced with overload protection
LF	Over-speeding
EU	Frequency restricted/reduced with IPM temperature protection
PF	Drive board temperature sensor error
E9	Indoor unit full water error
P9	AC contactor protection
E2	Anti-freezing protection
PE	Temperature drift protection
PP	AC input voltage abnormal
Pd	Sensor connection protection
U5	Whole unit current sensing circuit error
U3	DC bus voltage drop error
U7	4-way valve reversing error
L3	Outdoor fan 1 error protection
H6	Motor stalling
LA	Outdoor fan 2 error protection
U8	PG motor zero-crossing protection

Lennox AC Remote Control

Lennox Air Conditioner Mini Split Error Codes

Lennox Air Conditioner Mini Split Error Codes

Indoor and Outdoor Error Codes

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS) 2

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS) 6

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)3

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)4

 

Lennox AC Troubleshooting

Please check below items before asking for maintenance.

Phenomenon: Indoor unit can’t receive remote controller’s signal or remote controller has no action.

Check items:

1. Whether remote controller is within the signal receiving range?
2. Whether there are obstacles?
3. Whether remote controller is pointing at the receiving window?
4. Is sensitivity of remote controller low; fuzzy display and no display?
5. No display when operating remote controller?
6. Fluorescent lamp in room?

Solution:

1. Signal receiving range is 8m.
2. Remove obstacles.
3. Select proper angle and point the remote controller at the receiving window on indoor unit.
4. Check the batteries. If the power of batteries is too low, please replace them.
5. Check whether remote controller appears to be damaged. If yes, replace it.
6. Take the remote controller close to indoor unit.

Phenomenon: No air emitted from indoor unit

Check items:

1. Air inlet or air outlet of indoor unit is blocked?
2. Under heating mode, indoor temperature is reached to set temperature?
3. Heating mode is turned on just now?

Solution:

1. Eliminate obstacles.
2. After reaching to set temperature, indoor unit will stop blowing out air.
3. In order to prevent blowing out cold air, indoor unit will be started after delaying for several minutes, which is a normal phenomenon.

Phenomenon: Air conditioner can’t operate

Check items:

1. Power failure?
2. Is plug loose?
3. Air switch trips off or fuse is burnt out?
4. Wiring has malfunction?
5. Unit has restarted immediately after stopping operation?
6. Whether the function setting for remote controller is correct?

Solution:

1. Wait until power recovery.
2. Reinsert the plug.
3. Ask professional to replace air switch or fuse.
4. Ask professional to replace it.
5. Wait for 3min, and then turn on the unit again.
6. Reset the function.

Phenomenon: Mist is emitted from indoor unit’s air outlet

Check items: Indoor temperature and humidity is high?

Solution: Because indoor air is cooled\rapidly. After a while, indoor temperature and humidity will be decrease and mist will disappear.

Phenomenon: Cooling ( heating) effect is not good

Check items:

1. Voltage is too low?
2. Filter is dirty?
3. Set temperature is in proper range?
4. Door and window are open?

Solution:

1. Wait until the voltage resumes normal.
2. Clean the filter.
3. Adjust temperature to proper range.
4. Close door and window.

Phenomenon: Outdoor unit has vapor

Check items: Heating mode is turned on?

Solution: During defrosting under heating mode, it may generate vapor, which is a normal phenomenon.

Phenomenon: ”Water flowing” noise

Check items: Air conditioner is turned on or turned offjust now?

Solution: The noise is the sound of \refrigerant flowing inside the unit, which is a normal phenomenon.

Phenomenon: Cracking noise

Check items: Air conditioner is turned on or turned offjust now?

Solution: This is the sound of frictioh caused by expansion and/or contraction of panel or other parts clue to the change of temperature.

Lennox Air Conditioner Manual PDF