Er IS Error on LG French Door Refrigerator? Comprehensive Fix Guide

The LG Refrigerator Error “Er IS” (often misread as Er 15) indicates a malfunction within the Icemaker Sensor circuit. Specifically, the main control board has detected an abnormal signal—or a total lack of signal—from the sensor responsible for monitoring the ice compartment’s temperature or the icemaker’s position. It is a communication breakdown in the cooling logic.

In my thirty years of turning wrenches on appliances, I’ve seen this one more times than I can count. You’re likely staring at a dead ice dispenser, hearing a faint humming or clicking from the door, or perhaps your water is still cold but the cubes have stopped falling. Don’t go shopping for a new fridge just yet; this is a classic “parts-and-patience” fix that we can handle right in your kitchen.

Symptoms of the Er IS Fault

When the “IS” error strikes, the refrigerator doesn’t always just quit. It usually gives you a few “tells” before the display board starts flashing that code. If you notice any of the following, you’re dealing with an icing system failure:

• The “Frozen” Display: The control panel is locked on the Er IS code, and none of the buttons for “Crushed” or “Cubed” ice respond to your touch.
• Intermittent Ice Production: You might get a batch of ice once every two days, or the tray might fill with water but never dump the cubes because the sensor can’t tell if they’re frozen.
• The Door Buzz: You hear a faint, high-pitched buzzing or “struggling” sound coming from the left-side French door. This is often the ice room fan trying to spin through a block of frost.
• Lukewarm Dispenser Water: While the main cabin stays cold, the water coming from the door feels room temperature because the cooling loop for the ice room has been shut down by the error.

Technical Explanation of the Fault

To fix this, you have to understand the “Why.” In an LG French Door unit, the icemaker isn’t just a plastic tray; it’s a micro-environment. Here is what’s actually happening behind the scenes:

1. Sensor Thermistor Failure: The most common culprit is the thermistor (a temperature-sensitive resistor). Over years of freezing and thawing, the casing can develop microscopic cracks. Moisture seeps in, shorts the internal component, and sends a “nonsense” voltage back to the control board. The board doesn’t know the temperature, so it kills the system for safety.

2. Ice Room Fan Obstruction: LG fridges use a dedicated fan to blow cold air into the door’s ice compartment. If your door gasket has a tiny leak, humid air enters, hits that cold fan, and turns into solid ice. When the fan stops spinning, the sensor detects a massive temperature spike, triggering the Er IS code because the “Ice Sensor” environment is out of spec.

3. Wiring Harness Fatigue: Think about how many times you open that left door. Every time you do, the bundle of wires at the top hinge flexes. Eventually, the thin communication wire for the ice sensor can fray or snap inside the insulation. It looks fine on the outside, but the “juice” isn’t getting through.

4. Voltage Spikes: Modern LG boards are essentially small computers. A local power flicker can “scramble” the logic that reads the sensor. While rare, the board itself can sometimes fail to interpret a perfectly good signal from the sensor.

Troubleshooting & Replacement Instructions

Listen close: Before you start tearing things apart, unplug the refrigerator. Working on a live circuit with wet ice nearby is a recipe for a bad day. Let’s get to work.

1. The Hard Reset:
   Before buying parts, give the logic board a “brain scrub.” Unplug the unit from the wall and leave it dead for at least 10 minutes. This allows the capacitors on the main PCB to discharge. Plug it back in. If the code clears and stays away for 24 hours, it was likely a temporary software glitch. If it comes back immediately, proceed to step two.
2. Access the Ice Room:
   Open the left-hand door. You’ll need to remove the ice bucket first. Look for the decorative plastic shroud covering the icemaker assembly. There are usually two Phillips head screws holding this panel in place. Remove them and gently pry the panel forward. Be careful—there are plastic clips that like to snap if you’re too aggressive.
3. The Great Thaw:
   Once the panel is off, check for frost. If you see a wall of white ice, that’s your problem. Use a hairdryer on a **low heat** setting (high heat will warp the plastic liner) or a steamer to melt every trace of ice around the fan and the sensor.

   SAFETY WARNING: Do not use a heat gun or an open flame. You will melt the thin plastic walls of your $3,000 refrigerator in seconds.

4. Test the Sensor with a Multimeter:
   Locate the wire harness leading to the icemaker. Unplug the connector. Set your multimeter to the Ohms (Ω) setting (20k range). Probe the wires leading to the thermistor. At room temperature (77°F), you should see roughly 10k Ohms. If you see “OL” (Open Line) or 0 Ohms, the sensor is dead and must be replaced.
5. Replacing the Icemaker/Sensor Assembly:
   On most modern LG models, the sensor is integrated into the icemaker motor mold or the fan housing. Unscrew the mounting bracket and disconnect the remaining wire harnesses. Slide the old unit out and slide the new one in. Ensure the connectors “click” firmly into place—a loose plug is just as bad as a broken wire.
6. Check the Door Hinge Wiring:
   If the sensor tests fine, pop the plastic cover off the top left door hinge. Look for any wires that look pinched, kinked, or discolored. I’ve found many “IS” errors were actually just a broken wire right at the pivot point. If you find a break, you’ll need to solder it or use a heat-shrink butt connector.

How to Prevent Error Er IS

Once you’ve got those ice cubes clinking again, you don’t want to do this repair a second time. Here is the veteran’s secret to longevity:

• Seal the Gaskets: Take a damp cloth and wipe down the rubber gaskets on your doors once a month. Then, apply a very thin layer of silicone lubricant or even Vaseline to the hinge side. This ensures an airtight seal, preventing the moisture that causes the ice-clogs leading to the IS error.
• Don’t Pack the Freezer: If you block the air vents in the main freezer compartment, the fridge has to work twice as hard to pump cold air into the door. This causes temperature fluctuations that kill sensors. Keep at least 2 inches of space around the vents.
• Install a Surge Protector: These LG boards are sensitive. A dedicated appliance surge protector can save the main PCB from the “brain damage” that leads to false sensor errors.

Frequently Asked Questions

Q: Is Er IS the same as Er 15?
Yes. Because of the way the 7-segment LED display is designed, the “IS” looks exactly like “15.” Both codes refer to the Icemaker Sensor. The troubleshooting steps are identical.

Q: Can I still use the refrigerator while it has this code?
Technically, yes. The fridge and freezer should continue to stay cold. However, the control board may eventually disable other features if it thinks the internal temperature is unsafe. It’s best to fix it within a week of the code appearing.

Q: I replaced the icemaker and the code is still there. Now what?
If you’ve replaced the sensor/icemaker and checked the door hinge wiring, the fault lies in the Main Power Control Board (located on the back of the fridge). The relay or the logic circuit that processes the sensor’s voltage has likely failed.