Need help finding Lennox mini split air conditioner error codes? Error codes can display on either the indoor or outdoor unit. Certain error codes mean different things. Knowing what each error code means can assist you in troubleshooting and fixing your Lennox AC unit.
Below you will find Lennox AC error codes for both the indoor and outdoor units. We have included flowcharts for troubleshooting what part needs to be replaced.
For any issues not covered on this page, here is the Lennox Owners website, and the Lennox Troubleshooting website. NOTE: Check your model number of Lennox AC before using the error codes as a reference.
Lennox Mini Split Air Conditioner Error Codes
Lennox mini-split heat pumps and air conditioners are ideal for heating and cooling spaces like add-on rooms where installing or extending duct work is not possible. This is why many people choose to install a split system. All Lennox AC error codes that may show on your display are below.
Lennox MS8 SERIES AC Error Codes
Lennox Air Conditioner Error Code = C5 Indoor control jumper is missing
Lennox Air Conditioner Error Code = E0 EEPROM failure
Lennox Air Conditioner Error Code = EE EEPROM failure
Lennox Air Conditioner Error Code = E1 Communication failure between indoor unit and outdoor unit
Lennox Air Conditioner Error Code = E2 Indoor coil freeze protection – All system functions are terminated except indoor fan
Lennox Air Conditioner Error Code = E3 Outdoor coil blockage or low refrigerant due to leak
Lennox Air Conditioner Error Code = E4 Discharge line temperature protection
Lennox Air Conditioner Error Code = E5 Compressor overcurrent protection
Lennox Air Conditioner Error Code = E6 Communication failure between indoor unit and outdoor unit
Lennox Air Conditioner Error Code = FH Anti-freezing upper and lower limit range
Lennox Air Conditioner Error Code = FO Indoor coil is gathering refrigerant
Lennox Air Conditioner Error Code = F1 Indoor ambient sensor (RT1) open or short circuited
Lennox Air Conditioner Error Code = F2 Indoor coil sensor (RT2) open or short circuited
Lennox Air Conditioner Error Code = F3 Outdoor ambient sensor (RT4)open or short circuit
Lennox Air Conditioner Error Code = F4 Outdoor coil sensor (RT3) open or short circuit
Lennox Air Conditioner Error Code = F5 Discharge line sensor (RT5) error
Lennox Air Conditioner Error Code = F6 Compressor overload limit issue
Lennox Air Conditioner Error Code = F8 High current limit issue
Lennox Air Conditioner Error Code = F9 Discharge line temperature too high
Lennox Air Conditioner Error Code = HC Power factor correction protection
Lennox Air Conditioner Error Code = H1 Defrosting (heat pump only)
Lennox Air Conditioner Error Code = H3 Compressor overload protection sensor (CT1.2) malfunction
Lennox Air Conditioner Error Code = H4 Compressor high temperature protection
Lennox Air Conditioner Error Code = H5 Intelligent Power Module (IPM) module protection
Lennox Air Conditioner Error Code = H6 Indoor fan not communicating
Lennox Air Conditioner Error Code = LP Indoor and outdoor unit mismatch
Lennox Air Conditioner Error Code = L3 Outdoor DC fan motor malfunction
Lennox Air Conditioner Error Code = L9 Power factor protection
Lennox Air Conditioner Error Code = PH High voltage protection
Lennox Air Conditioner Error Code = PL Low voltage protection
Lennox MPA012S4S-1L AC Error Codes
Lennox Air Conditioner Error Code = EO Outdoor EEPROM error
Lennox Air Conditioner Error Code = E2 Communication error between outdoor unit and all indoor units
Lennox Air Conditioner Error Code = E3 Communication error between outdoor unit main control and IPM control
Lennox Air Conditioner Error Code = E4 Temp sensor error
Lennox Air Conditioner Error Code = E5 High or Low voltage protection
Lennox Air Conditioner Error Code = E8 Outdoor DC fan speed error
Lennox Air Conditioner Error Code = F1 Indoor unit #1 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = F2 Indoor unit #2 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = F3 Indoor unit #3 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = F4 Indoor unit #4 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = F5 Indoor unit #5 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = F6 Indoor unit #6 coil outlet temp, sensor error
Lennox Air Conditioner Error Code = P1 High pressure switch open
Lennox Air Conditioner Error Code = P2 Low pressure switch open
Lennox Air Conditioner Error Code = P3 Outdoor Compressor current overload sensed
Lennox Air Conditioner Error Code = P4 High temperature sensed at compressor discharge line
Lennox Air Conditioner Error Code = P5 High temperature sensed at outdoor coil
Lennox Air Conditioner Error Code = Lpe Inverter module (IPM) error
Lennox Universal Mini-Split Error Codes
NOTE: All indoor units provide fault code information with either a digital LED display or with flash codes.
Lennox Air Conditioner Error Code = E0 Indoor unit EEPROM error
Lennox Air Conditioner Error Code = E1 Communication error between indoor unit and outdoor units
Lennox Air Conditioner Error Code = E3 Indoor fan speed error
Lennox Air Conditioner Error Code = E4 Indoor Return air temperature sensor error
Lennox Air Conditioner Error Code = E5 Indoor coil temperature sensor error
Lennox Air Conditioner Error Code = EC Low refrigerant
Lennox Air Conditioner Error Code = EE High water level alarm
Lennox Air Conditioner Error Code = F0 Outdoor current overload sensed
Lennox Air Conditioner Error Code = F1 Outdoor ambient temperature sensor error
Lennox Air Conditioner Error Code = F2 Outdoor coil temperature sensor error
Lennox Air Conditioner Error Code = F3 Compressor discharge temperature sensor error
Lennox Air Conditioner Error Code = F4 Outdoor unit EEPROM error
Lennox Air Conditioner Error Code = F5 Outdoor unit fan speed error
Lennox Air Conditioner Error Code = P0 Inverter module IPM error
Lennox Air Conditioner Error Code = P1 High or Low voltage protection
Lennox Air Conditioner Error Code = P3 Outdoor unit low temperature lockout
Lennox Air Conditioner Error Code = P4 Compressor drive error
Lennox Air Conditioner Error Code = P6 Compressor high-pressure or low-pressure switch open
(Indoor Unit Sticker Shown – ALL Indoor Units 09/24)
Lennox Air Conditioner Parts
Lennox Split AC Indoor Unit Error Codes
Lennox AC Error Codes – Indoor Units 1
Lennox AC Error Codes – Indoor Units 2
Lennox AC Indoor Unit Error Fault Code E0
Lennox AC Indoor Unit Error Fault Code E1
Lennox AC Indoor Unit Error Fault Code E3
Lennox AC Indoor Unit Error Fault Code E4
Lennox AC Indoor Unit Error Fault Code E5
Lennox AC Indoor Unit Error Fault Code EC
Lennox AC Indoor Unit Error Fault Code F2
Lennox AC Indoor Unit Error Fault Code F3
Lennox AC Indoor Unit Error Fault Code F4
Lennox AC Indoor Unit Error Fault Code F5
Lennox Split AC Main Control Board Error Codes
Lennox AC Main Board Error Codes LED Display 1
Lennox AC Main Board Error Codes LED Display 2
Lennox AC Main Board Fault Code LED 1
Lennox AC Main Board Fault Code LED 3
Lennox AC Main Board Fault Code LED 2
Lennox AC Main Board Fault Code LED 5
Lennox AC Main Board Fault Code LED 6
Lennox AC Fan Motor DC Voltage Input and Output
Lennox AC Fan Motor Troubleshooting
Lennox Split AC Manuals For Download
Lennox MS8 SERIES Installation And Service Procedures: Manual for Indoor And Outdoor Error Codes
LENNOX SPLIT AIR CONDITIONER MANUALS IN PDF HERE
For model numbers LI012CI-160P432, LI012CO-160P432, LI018CI-160P432, LI018CO-160P432, LI024CI-160P432, LI024CO-160P432, LI012HI-160P432, LI012HO-160P432, LI018HI-160P432, LI018HO-160P432, LI024HI-160P432 and LI024HO-160P432.
LENNOX MINI-SPLIT SYSTEMS SERVICE MANUAL
Lennox Mini-Split Service Manual PDF is here if further troubleshooting is needed.
LENNOX SERVICE MANUAL FOR ROOM AIR CONDITIONER (Inverter Split-Type) PDF is here.
Manual is applicable only to the following models – LNIV2610, LNIV3510, LNIV5010, LNIV6510.
If you need more schematics or ways to troubleshoot your Lennox AC unit, please leave a comment below and we will assist you.
I’m experiencing a code H5 on my Lennox mini split heat pump what does this mean and what do I need to do to correct it.
What is a bF code.
I noticed it on my daughter’s unit so I looked in my son’s room and my room and they all had the same reading on the display.
I thought that it was odd because we don’t mess with the temp.
In the house it stays at 68.
I’ve looked in the book and all the paperwork for the unit but no luck.
It is a Lennox heat pump unit.
It appears to be back to the temp.
On the display after I noticed the air vent door was not all the way open.
I manually open and closed it and it appeared to start blowing air again.
Any ideas to why they displayed that on the LED screen instead of the temperature.
Also why did it appear to start working again after I manually moved the vent door.