Step-by-Step DIY Fix Guide
- SAFETY: Unplug the refrigerator before accessing the ice maker compartment.
- Remove all food from the freezer and transfer to a cooler with ice.
- Unplug the refrigerator and leave the freezer door open for 4–6 hours to allow a complete thaw of the ice maker compartment.
- After thawing, dry the interior with a cloth and check that the ice maker fan blade rotates freely by hand.
- Plug in the refrigerator and listen for the ice maker fan to start — it should run within a few minutes as the compartment cools.
- If the fan does not start or IS returns after thawing, call an LG-authorized technician to test the fan motor and sensor.
If the warning comes back after restart
- If the door closes normally but the warning keeps returning, the latch or switch path becomes more likely than a simple alignment issue.
- If airflow still seems weak after the basic checks, the fan path or a deeper obstruction becomes more likely.
- If the warning returns immediately after a clean restart, the sensor or wiring path becomes more likely than a one-time glitch.
What This Error Means
Error IS on your LG refrigerator means: The ice maker compartment fan or its temperature sensor is not functioning correctly. The ice maker fan circulates cold air around the ice tray — without it, ice production slows or stops and ice quality deteriorates. Also displayed as 1S on some LG models. The refrigerator's self-diagnostic system has detected this condition.
The most frequent cause is ice build-up blocking the ice maker fan blade — fan is physically jammed by frost. Work through the causes and fix steps below in order — many LG refrigerator errors are resolved without a service call.
Many cases of IS can be resolved by the homeowner. The steps below cover the full DIY checks — if they do not resolve the error, a technician is needed.
Refrigerator fan errors are often caused by ice build-up rather than motor failure. A complete manual defrost — unplugging and leaving both doors open for 24–48 hours — resolves the majority of fan faults caused by frost. Only if the fan still does not start after a full thaw is motor replacement needed.
Most Likely Cause by Symptom
The LG refrigerator may stop, pause, or refuse to complete the cycle normally.
Likely cause: Ice build-up blocking the ice maker fan blade — fan is physically jammed by frost
Check first: SAFETY: Unplug the refrigerator before accessing the ice maker compartment.
The appliance may fail to start because the door or lock state cannot be confirmed.
Likely cause: Ice maker fan motor failure
Check first: Remove all food from the freezer and transfer to a cooler with ice.
The warning may return immediately because the appliance is detecting an internal fault.
Likely cause: Ice maker compartment sensor (thermistor) failure
Check first: Unplug the refrigerator and leave the freezer door open for 4–6 hours to allow a complete thaw of the ice maker compartment.
Common Causes
- Ice build-up blocking the ice maker fan blade — fan is physically jammed by frost
- Ice maker fan motor failure
- Ice maker compartment sensor (thermistor) failure
- Wiring harness fault to the ice maker fan or sensor
What Not to Do
- Do not chip away ice around the fan blade with a sharp tool — this damages the fan and may puncture the evaporator coil
Model and Display Variation Notes
Model-family notes
- LG refrigerator display wording and code formats can vary by series.
- If your model behaves differently, check the owner manual before trying any deeper maintenance step.
- Some models may display the same fault as IS, 1S.
Display and panel differences
- Some control panels show this issue as IS, 1S instead of only IS.
- Panel wording and whether the code appears with letters, numbers, or a longer variant can differ by model family.
Parts, Tools and Service Options
Common parts
- Ice maker fan motor if motor has failed ($20–$60)
- Ice maker sensor/thermistor if sensor has failed ($15–$40)
Manual and model check
Check your exact model and manual before ordering any LG refrigerator parts.
Service option
LG service visit if the warning returns after the basic checks are complete.
Suggestions in this section are organized to support the troubleshooting flow first. Any future affiliate relationships should be disclosed clearly.
When Not to Keep Troubleshooting
IS returns after a full thaw of the ice maker compartment
- Ice maker fan does not spin freely by hand after thawing
How to Prevent It Recurring
- Check that the freezer door seals fully on every closure — a poor gasket seal allows warm humid air to enter and frost the ice maker fan
Related Error Codes
IF
LG refrigerator error IF usually means the ice maker compartment fan is not running normally.
EID
The temperature sensor inside the freezer ice maker has failed or is reading outside the expected range. The refrigerator cannot monitor the ice maker tray temperature and has disabled ice production to prevent a malfunction.
FF
LG refrigerator error FF usually means the freezer evaporator fan is not circulating cold air through the cabinet properly.
Extra notes
- This page is based on LG support material and stays conservative where model-specific guidance may vary.
- The goal is to help you identify safe first checks before you move into parts, service, or model-specific manual lookup.
Source and model notes
Last reviewed: 2026-04-08
Based on: Based on LG support material and edited into consumer-safe guidance for the exact code family on this page.
Model coverage note: LG refrigerator code meanings can vary by series, control panel, and model family, so use this page as a safe starting point rather than a replacement for the model-specific manual.
Important: FixThisError is an independent guide, not the manufacturer. Use your model-specific manual when the panel wording or behavior differs.
Always disconnect power before inspecting appliances. If unsure, contact a licensed appliance technician.