LG Freezer IS Error: Ice sensor fault
LG freezer error — here’s what you need to know. The IS error code on your LG freezer indicates an ice sensor fault. This is a Medium severity issue. What Does IS Mean on an LG Freezer? The IS code indicates a problem with the ice sensor circuit, which monitors conditions inside the freezer to […]
~50%
DIY Fixable
From 5
Typical Repair Cost
1–2 hours
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
Maybe. The freezer will likely continue cooling, but automatic defrost or ice-sensing functions are unreliable. Monitor internal temperatures and food condition closely until the sensor is repaired
Can I reset the code?
Yes. Unplugging the unit for 5 minutes will clear the fault code. If the sensor is faulty the IS code will reappear once the board completes its startup diagnostics
When to stop immediately?
Stop if you notice: Heavy frost accumulation blocks the door seal or air vents, The freezer interior temperature climbs above safe storage levels.
Symptoms You May Notice
Unusual frost patterns inside the cabinet
Ice accumulates unevenly on the walls or floor of the freezer because the sensor-driven defrost cycle is not operating on schedule
Ice-making or frost-prevention cycle not running
The appliance skips or runs the automatic defrost or ice cycle continuously because the sensor signal is unreliable
IS code on the control panel display
The IS fault code appears on the display, sometimes flashing to indicate an active sensor circuit error
Inconsistent temperature performance
The freezer runs too hot, too cold, or cycles erratically because the control board receives inaccurate temperature readings from the faulty sensor.
Possible Causes
Failed ice sensor thermistor
The thermistor element has drifted out of its rated resistance range due to age or moisture damage, causing the board to log a fault
Requires ProfessionalDisconnected or corroded sensor connector
The wiring connector linking the sensor to the main harness has come loose or corroded, interrupting the signal
DIY PossibleDefective control board sensor input
The control board's sensor-reading circuit has failed, generating a false IS fault even when the sensor itself is functional
Requires ProfessionalSafe Checks You Can Do
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1
Locate and reseat the ice sensor connector
Unplug the freezer and locate the ice sensor (typically clipped to the evaporator or rear interior wall). Disconnect and firmly reconnect the wiring connector, checking for corrosion or bent pins
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2
Power-cycle the freezer
Plug the freezer back in and wait 10 minutes for the control board to reinitialize. Check whether the IS code clears from the display
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3
Inspect the sensor for physical damage
Visually examine the sensor body for cracks, moisture ingress, or ice encasing the sensor. Gently clear any frost from around the sensor and its mounting clip
When to Call a Professional
Contact a qualified technician if:
- Sensor resistance reading is outside the manufacturer's specified range — thermistor replacement needed
- Connector shows corrosion or burn marks on the terminals
- Code returns immediately after a power cycle with no visible sensor damage
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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