Lennox AC Error Codes

If any error occurs in your air conditioner, indoor display shows error codes. Once you nail down the issue you can easily call in a professional, or fix the issue yourself. To help you out we have listed down the most common error codes of Lennox AC.

Indoor Unit Error Display

Error CodesCause
E0EEPROM parameter error
E1Indoor/outdoor units communication protection
E2Zero-crossing signal error
E3Indoor fan speed out of control
E5Open or short circuit of outdoor temperature sensor or outdoor unit EEPROM parameter error
E6Open or short circuit of room or evaporator temperature sensor
E7Outdoor fan speed out of control
P0IBM malfunction or IGBT over-strong current protection
P1Over voltage or too low voltage protection
P2Temperature protection of compressor top
P4Inverter compressor drive error

Lennox Split AC

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.

Error CodesMeaning
F1Return air temperature sensor open/ short circuited
P6Drive board communication error
F2Evaporator temperature sensor open/ short circuited
H3Compressor overheating protection
b5Indoor unit liquid valve temperature sensor open/short circuited
LPIndoor and outdoor units unmatched
b7Indoor gas valve temperature sensor open/ short circuited
dnCommunication line misconnected or expansion valve error
P7IPM temperature sensor open/short circuited
E7Running mode conflict
F3Outdoor ambient temperature sensor open/ short circuited
FoPump-down
F4Outdoor unit condenser mid-tube temperature sensor open/short circuited
C5Jumper error
F5Discharge temperature sensor open/ short circuited
H1Forced defrosting
E6Indoor and outdoor communication error
LcCompressor startup failure
PLDC bus under-voltage protection......
E4High discharge temperature protection
PHDC bus over-voltage protection
E8Overload protection
U1Compressor phase current sensing circuit error
E5Whole unit over-current protection
HECompressor demagnetization protection
P5Over phase current protection
HcPFC protection
H7Compressor desynchronizing
P8IPM Temperature Protection
H5IPM Current protection
L9Over-power protection
LdCompressor phase loss/reversal protection
F0System charge shortage or blockage protection
F8Frequency restricted/reduced with whole unit current protection
PUCapacitor charging error
IPMFrequency restricted/reduced with
EnCurrent protection
E1High pressure protection
F9Frequency restricted/reduced with high discharge temperature
E3Low pressure protection
FHFrequency restricted/reduced with antifreezing protection
LECompressor stalling
F6Frequency restricted/reduced with overload protection
LFOver-speeding
EUFrequency restricted/reduced with IPM temperature protection
PFDrive board temperature sensor error
E9Indoor unit full water error
P9AC contactor protection
E2Anti-freezing protection
PETemperature drift protection
PPAC input voltage abnormal
PdSensor connection protection
U5Whole unit current sensing circuit error
U3DC bus voltage drop error
U74-way valve reversing error
L3Outdoor fan 1 error protection
H6Motor stalling
LAOutdoor fan 2 error protection
U8PG motor zero-crossing protection

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

Lennox AC Remote Control
Lennox AC Remote Control

Lennox Air Conditioner Mini Split

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) 2

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS) 6
INDOOR UNIT DISPLAY CODES (ALL SYSTEMS) 6

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)
INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)3
INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)3

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)4
INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)

Lennox Rooftop

Climatic 50 Roof-Top, Aircoolair & Compactair Version 24

Error CodesProblem
001Airflow
004Filters, Clogged up
005Filters, Missing
006Recovery Module, Filters, Clogged up
011Electric heating elements
012High Temperature, Blowing
013Low Temperature, Ambient
022Low Temperature, Blowing
023High Temperature, Ambient
051Recovery Module, Motor failure
052Recovery Module, Wheel failure
081Temperature sensor, Ambient
082Humidity sensor, Ambient
083Temperature probe, Outside
084Humidity sensor, Outside
085Temperature probe, Blower
086Circuit 1, Temperature sensor, Water condenser Outlet
087Circuit 2, Temperature sensor, Water condenser Outlet
088Temperature sensor, return or Mixing air
096Low temperature, Water Condenser
097High temperature, Water Condenser

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

Lennox Rooftop Service Manual


*If you can't find the code you're looking for on our site, please let us know, and we'll update our database as soon as possible.

10 thoughts on “Lennox AC Error Codes”

  1. ı need your help
    ı have an inverter mninisplit lennox model lxgıhhmd01815p4
    code error f2
    what the problem..

    Reply

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