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
Lennox AC Error Codes and Troubleshooting

LNIV2610 LNIV3510 LNIV5010 LNIV6510

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 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
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

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

Lennox AC Remote Control
Lennox AC Remote Control

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 Air Conditioner Mini Split Error Codes

Lennox Air Conditioner Mini Split Error Codes
Lennox Air Conditioner Mini Split Error Codes

Indoor and Outdoor Error Codes

30 KBTU SYSTEM STATUS OR ERROR CODES — OUTDOOR CHARACTER DISPLAY 2
30 KBTU SYSTEM STATUS OR ERROR CODES — OUTDOOR CHARACTER DISPLAY 2

 

30 KBTU SYSTEM STATUS OR ERROR CODES — OUTDOOR CHARACTER DISPLAY
30 KBTU SYSTEM STATUS OR ERROR CODES — OUTDOOR CHARACTER DISPLAY

 

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)4

 

INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)-MS7 SERIES UNITS — MINI-SPLIT SINGLE-ZONE SYSTEMS
INDOOR UNIT DISPLAY CODES (ALL SYSTEMS)-MS7 SERIES UNITS — MINI-SPLIT SINGLE-ZONE SYSTEMS

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








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