LG Refrigerator Error Er IS: Ice Maker Sensor Error — How to Fix

Understanding LG Error Code Er IS

The Er IS code appears on the digital display of many LG side‑by‑side and French‑door refrigerators. It tells the control board that the ice‑maker temperature sensor isn’t providing a valid reading. When the sensor reports an out‑of‑range temperature, the board stops the ice‑maker motor to avoid producing malformed cubes or overheating the water inlet valve.

Why does this matter? The ice‑maker draws a significant amount of power; running it with a faulty sensor can overheat the motor and eventually damage the water inlet valve. also, the error can mask other refrigeration problems, making later diagnosis harder.

Quick Check

1. Power Cycle – Unplug the fridge for 60 seconds, then restore power.
2. Observe – If Er IS disappears, the issue was a momentary glitch; monitor the ice‑maker for the next 24 hours.
3. Proceed – If the code returns, follow the detailed steps below.

Symptoms

• Ice maker stops producing cubes or makes only a few cubes per cycle.
• The control panel flashes “Er IS” repeatedly.
• You may hear the ice‑maker motor click without the usual water‑fill sound.
• In rare cases the freezer compartment feels slightly warmer because the ice‑maker cycle aborts early.

Root Causes

• Faulty temperature sensor – The thermistor can wear out after many freeze‑thaw cycles.
• Insufficient water flow – A clogged filter or weak inlet valve can cause abnormal temperature readings.
• Loose wiring harness – Vibration from the compressor may loosen the connector between the sensor and the main board.
• Control board glitch – A stray voltage spike can corrupt the sensor reading, prompting the error.
• Power interruption – Frequent outages can leave the sensor in an undefined state.

Similar sensor‑related errors appear on other brands. For example, Bosch dishwashers use error codes like E01 and E09 to indicate water‑flow or heating‑element problems that also rely on temperature sensing.

Step‑by‑Step Repair

1. Quick Power Reset

Unplug the refrigerator or turn off the dedicated circuit breaker for at least 60 seconds. This clears any transient fault that may have triggered Er IS. After the pause, restore power and watch the control panel for the error code. If Er IS disappears, the problem was a temporary glitch.

Pro tip: Leave the doors open for a minute after power is restored; this helps the compressor settle faster.

2. Verify Ice Maker Power

Open the freezer door and locate the ice‑maker module, usually hidden behind a removable front panel. Using a Phillips #2 screwdriver, remove the panel. With a digital multimeter set to AC volts, probe the ice‑maker’s power connector. You should see line voltage (120 V AC in North America, 230 V AC elsewhere). No voltage indicates a wiring fault or a blown fuse on the control board.

Safety warning: Always test voltage with the appliance unplugged whenever you need to access internal wiring. Re‑plug only after the test is complete.

3. Inspect Water Supply and Filter

A restricted water line can cause the sensor to think the ice‑maker is stuck. Locate the water inlet valve behind the fridge, disconnect the hose, and inspect the filter screen for debris. Run water through the valve into a bucket; you should see a steady flow of at least 1 liter per minute. Low flow points to a clogged filter or a failing valve.

Pro tip: Replace the filter every six months to keep water pressure consistent.

4. Test the Ice Maker Temperature Sensor

With the freezer door still open, locate the small thermistor attached to the ice‑maker’s base. Disconnect the sensor connector and set the multimeter to resistance (Ω). At room temperature the sensor should read roughly 10 kΩ; at freezer temperature (‑18 °C) it should drop to about 2 kΩ. A constant reading or an open circuit means the sensor is defective.

Safety warning: Do not touch exposed wires with wet hands; moisture can cause electric shock.

5. Replace a Faulty Sensor

If the continuity test fails, remove the sensor by pulling the retaining clip with a flat‑head screwdriver. Snap the new sensor’s clip into place and reconnect the wiring harness. Make sure the sensor sits flush against the ice‑maker’s base so temperature is read accurately.

Pro tip: Handle the new sensor by its leads; bending the leads can cause future failures.

6. Reassemble and Run a Test Cycle

Replace the ice‑maker front cover, secure it with the Phillips #2 screws, and plug the refrigerator back in. On the control panel select the ice‑maker ‘ON’ mode (often a button with a snowflake icon). Wait 1‑2 hours for the first batch of ice to form. Verify that the Er IS code no longer appears.

Pro tip: If the code returns after the first cycle, double‑check the water inlet valve for leaks or intermittent operation.

7. Final Safety Check

Inspect all wiring connections for tightness and look for any water droplets around the valve and sensor. Dry any moisture with a lint‑free cloth before closing the freezer door. This prevents short‑circuit conditions that could re‑trigger error codes.

Pro tip: Keep a small notebook of the resistance values you measured; it helps future troubleshooting.

Repair Cost Estimate

Prices vary by model and region. LG ships replacement parts through authorized distributors; buying from a reputable seller reduces the risk of counterfeit components.

Warranty & Support

LG provides a limited 1‑year parts and labor warranty on most residential refrigerators, extended to 5 years for the compressor in many models. If your unit is still under warranty, call LG support at 1‑800‑243‑0000 before ordering parts. Have your model number and serial number ready; they are located on the interior wall of the freezer compartment. The warranty does not cover damage caused by user‑performed repairs, so weigh the risk before opening the unit.

Model‑Specific Notes

• LG LFXS26973 – The sensor on this French‑door model is accessed from the left side of the freezer; a T20 Torx is required to remove the retaining bracket.
• LG LRMDS3006 – This side‑by‑side unit uses a snap‑in sensor with a plastic cover that can crack if pried aggressively.
• LG LFXR25996 – Some owners report that a faulty water filter can trigger Er IS even when the sensor is healthy; replace the filter first before testing the sensor.

Diagnostic Tips Using LG SmartThinQ

If your refrigerator is connected to the LG SmartThinQ app, you can view error logs remotely. The app often provides a “Reset Ice Maker” button that performs a soft reset without unplugging the unit. Use this feature after you replace the sensor to confirm the error has cleared before running a full ice‑making cycle.

Preventive Maintenance Tips

• Clean the water filter every six months to maintain proper flow to the ice maker.
• Check the ice‑maker door seal for frost buildup; excess ice can jam the sensor.
• Run a brief power‑cycle quarterly; this refreshes the control board’s memory and can prevent false error codes.
• Inspect the wiring harness annually for signs of corrosion or loosened terminals, especially after a power surge.

By staying on top of these small tasks, you reduce the chance of the Er IS code reappearing and keep your freezer running efficiently.

Related Error Codes

• Er IF – Indicates a problem with the ice‑maker’s fill sensor.
• Er FS – Signals a fault in the ice‑maker’s motor or its speed sensor.

Understanding these codes helps you pinpoint whether the issue is isolated to the temperature sensor (Er IS) or involves other ice‑maker components.

Quick Links to Other Guides

• Need help with a dishwasher error? Check out the LG Dishwasher error AE guide for leak detection issues: LG Dishwasher Error AE.
• For a deeper look at thermistor problems on LG appliances, see the LG Washing Machine tE article: LG Washing Machine Error tE.
• If you suspect a similar sensor fault on a Samsung fridge, read the Samsung Refrigerator SYMBOL‑ICE‑MAKER page: Samsung Refrigerator Ice‑Maker Error.
• For a comparable sensor‑related fault on a GE dishwasher, see the GE Dishwasher error C1 page: GE Dishwasher Error C1.

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