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WINDOW AC

Window AC error codes and blink patterns.

Single-unit room air conditioners often show faults as a blinking timer light or a beep count rather than a text code. Here’s what the common patterns mean.

Jump to: LG · Voltas · Samsung · Godrej · Blue Star · Carrier · Frigidaire · Friedrich

Before you search: window AC display panels vary a lot between model years. If your unit has no display at all, count how many times the timer/operation light blinks between pauses — that count is your code.
Safety first: burning smell, sparking, or a tripped breaker means a possible short circuit — cut power at the main board and call an electrician. Suspected gas leakage or refrigerant faults need a certified technician with proper equipment. See the full disclaimer before acting on any code.
LG
CodeLikely meaningWhat to check
E1Room temperature sensor open or shortSensor connector loose behind the front grille.
E2Evaporator coil sensor errorCheck the coil sensor clip and wiring.
ECCooling coil frost/temperature faultCheck for restricted airflow through the filter.
E3Overload / compressor protectionCheck for a dirty filter restricting airflow.
E4High pressure protectionCheck outdoor coil side isn’t blocked by debris.
E5Low voltage protectionCheck incoming supply voltage.
E6Control board communication faultInternal wiring fault — needs technician inspection.
E7Compressor overcurrent protectionCheck for restricted airflow or an aging compressor.
E8Refrigerant leak detectionNeeds a technician with gauges — not a DIY fix.
E9Display or keypad button stuckCheck the control panel buttons aren’t jammed.
Voltas
CodeLikely meaningWhat to check
F1Room temperature sensor errorSensor wiring near the intake grille.
F2Evaporator coil sensor errorCheck coil sensor position and connection.
3 beepsOverload / high current protectionCheck for a dirty filter restricting airflow.
F3Compressor coil sensor errorCheck the compressor coil sensor connection.
F4Overload protection trippedCheck outdoor coil side ventilation.
F5Control board communication errorInternal wiring fault — needs technician inspection.
F6EEPROM (memory) errorControl board fault, usually needs service.
F7High pressure protectionCheck for blocked airflow through the outdoor coil side.
F8Low voltage protectionCheck incoming supply voltage.
F9Compressor overcurrentCheck for restricted airflow or an aging compressor.
Samsung
CodeLikely meaningWhat to check
E1Room temperature sensor errorSensor connector behind the front panel.
E2Coil temperature sensor errorCheck coil sensor connection.
E3Overload protectionCheck for a dirty filter restricting airflow.
E4High pressure protectionCheck outdoor coil side ventilation.
E5Low voltage protectionCheck incoming supply voltage.
E6EEPROM (memory) errorControl board fault, usually needs service.
E7Fan motor errorCheck for obstruction or a failed motor.
E8Compressor overcurrentCheck for restricted airflow or an aging compressor.
E9Gas leak detectionNeeds a technician with gauges — not a DIY fix.
E10Fan motor errorCheck for obstruction or a failed motor.
Godrej
CodeLikely meaningWhat to check
E1Room sensor errorCheck sensor wiring behind the intake grille.
E2Coil sensor errorCheck the coil sensor clip.
E3Overload protectionCheck for a dirty filter restricting airflow.
E4High pressure protectionCheck outdoor coil side ventilation.
E5Low voltage protectionCheck incoming supply voltage.
E6EEPROM (memory) errorControl board fault, usually needs service.
E7Fan motor errorCheck for obstruction or a failed motor.
E8Compressor overcurrentCheck for restricted airflow or an aging compressor.
E9Gas leak detectionNeeds a technician with gauges — not a DIY fix.
E10Control board communication faultInternal wiring fault — needs technician inspection.
Blue Star
CodeLikely meaningWhat to check
E1Room temperature sensor errorSensor connector loose inside the unit.
P1High pressure / overload protectionCheck for blocked airflow through the outdoor coil side.
E2Coil temperature sensor errorCheck the coil sensor connection.
E3EEPROM (memory) errorControl board fault, usually needs service.
E4Control board communication faultInternal wiring fault — needs technician inspection.
P2Low pressure protectionPossible refrigerant shortage — needs gauge check.
P3Compressor overcurrent protectionCheck for restricted airflow or an aging compressor.
E5Fan motor errorCheck for obstruction or a failed motor.
E6Gas leak detectionNeeds a technician with gauges — not a DIY fix.
E7Low voltage protectionCheck incoming supply voltage.
Carrier
CodeLikely meaningWhat to check
E1Room temperature sensor errorCheck sensor connector behind the front panel.
E3Overload / high current protectionCheck filter cleanliness and airflow.
E2Coil temperature sensor errorCheck the coil sensor connection.
E4High pressure protectionCheck outdoor coil side ventilation.
E5Low voltage protectionCheck incoming supply voltage.
E6Control board communication faultInternal wiring fault — needs technician inspection.
E7EEPROM (memory) errorControl board fault, usually needs service.
E8Fan motor errorCheck for obstruction or a failed motor.
E9Compressor overcurrentCheck for restricted airflow or an aging compressor.
E10Gas leak detectionNeeds a technician with gauges — not a DIY fix.
Frigidaire (North America)
CodeLikely meaningWhat to check
E1Room temperature sensor errorCheck sensor connector behind the front panel.
E2Coil temperature sensor errorCheck the coil sensor connection.
HLHigh/low voltage protectionCheck incoming supply voltage.
LCLow refrigerant charge indicationPossible refrigerant issue — needs technician check.
FLFilter/coil frost conditionCheck for a dirty filter restricting airflow.
PFPower failure — unit needs manual resetPower-cycle the unit at the wall outlet.
F1Control board / EEPROM errorControl board fault, usually needs service.
E3Overload protectionCheck for a dirty filter restricting airflow.
E4Fan motor errorCheck for obstruction or a failed motor.
E5Communication / control faultInternal wiring fault — needs technician inspection.
Friedrich (North America)
CodeLikely meaningWhat to check
FLFilter/coil frost protectionCheck for a dirty filter restricting airflow.
E1Room temperature sensor errorCheck sensor connector behind the front panel.
E2Coil temperature sensor errorCheck the coil sensor connection.
E3Overload protectionCheck for a dirty filter restricting airflow.
E4Fan motor errorCheck for obstruction or a failed motor.
E5EEPROM (memory) errorControl board fault, usually needs service.
E6High voltage protectionCheck incoming supply voltage.
E7Low voltage protectionCheck incoming supply voltage.
E8Communication faultInternal wiring fault — needs technician inspection.
E9Compressor overcurrentCheck for restricted airflow or an aging compressor.
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Have a split, ductable or commercial unit instead? See split AC codes or commercial & VRF codes.