Air Conditioner E1 Error Code: Room Temperature Sensor Fault
Quick Answer
E1 on most window and portable air conditioners means the room temperature sensor (thermistor) has failed or is reading out of range. The sensor is usually a small probe near the air intake. E1 is used by GE, Frigidaire, Hisense, LG portable, and many other brands for this fault. The thermistor is an NTC type that reads approximately 10K-15K ohms at room temperature (varies by brand).
E1 on most window and portable air conditioners means the room temperature sensor (thermistor) has failed or is reading out of range. The sensor is usually a small probe near the air intake. E1 is used by GE, Frigidaire, Hisense, LG portable, and many other brands for this fault. The thermistor is an NTC type that reads approximately 10K-15K ohms at room temperature (varies by brand). If E1 appears intermittently, the sensor connector may be loose from vibration. If constant, the sensor has failed ($5-15 replacement). On window units, the sensor is accessible from the front panel. On portable units, remove the rear panel.
What Does the E1 Code Mean?
Air conditioner E1: room temperature sensor (thermistor) failed.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Symptoms You May Notice
- Generic airconditioner e1
Can you reset a Generic airconditioner to clear the E1 code?
Unplug 60 seconds.
Tools Required for Diagnosis
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
Follow brand-specific diagnosis in guide above.
Follow brand-specific diagnosis in guide above.
Check error codes.
Professional if needed.
Frequently Asked Questions
Repair cost?
DIY?
Worth it?
Last verified for technical accuracy on March 15, 2026