ER FS error code on an LG fridge: A troubleshooting guide

One of the error codes that you may see on your LG refrigerator is ER FS, which typically means the main control board has detected a problem with the freezer temperature sensor. This usually means the sensor is malfunctioning or there’s a wiring problem preventing the board from accurately reading the interior freezer temperatures.

Before you pick up the phone to call a repair technician, let’s walk through what you can do to fix this code.

If you find that you need a replacement part for your LG refrigerator, you can use your model number to find what you need at AppliancePartsPros.com. We also have thousands of free DIY troubleshooting and repair guides to help you fix your appliance yourself.

Disclaimer: The troubleshooting information provided in this article is based on general service manuals and may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes, and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

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Why the ER FS error shows up

You’ll usually notice the freezer and refrigerator sides of your fridge are warmer than usual when this error message appears. Some other symptoms could include:

• Little to no cold air circulation
• Longer compressor run times
• Continuous frost build-up
• Food spoilage in the fridge, freezer or both

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The root causes for an ER FS error may be:

• A failing or shorted freezer temperature sensor that sends incorrect resistance values to the main board.
• A loose connection, short or break in the wiring between the sensor and control board.
• A malfunctioning main control board (less common)

READ MORE: 8 DIY Safety Tips

Keep safety first

When working on any appliance, always keep safety first to avoid personal injury or damage to the appliance or parts. Here are some safety tips to keep in mind:

• Always power off and unplug your appliance or switch off the circuit breaker before attempting any maintenance or replacement work. This keeps you safe by preventing any risk of electric shock.
• Turn off the water supply at the outlet before beginning repairs. Keep towels ready to catch any residual water in the system when removing parts.
• If the appliance has recently been used, give it plenty of time to cool down before working on it.
• Take your time and don’t rush while working to prevent accidents and personal injuries.
• Work in a well-lit area so you can clearly see and access appliance parts.
• Keep your workspace free of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with wet hands. Make sure the work area is completely dry.
• Check the user manual to see if there are specific installation or safety instructions related to your appliance or replacement part.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause personal injury.
• Wear insulated work gloves to protect your hands from sharp metal parts and debris.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Consider wearing safety glasses and/or a dust mask when working with chemicals, dust or a large amount of debris to prevent irritation or injury.

READ MORE: How to prevent appliance fire hazards

ER FS troubleshooting steps

Step 1 – Check the connections

1. Turn off the fridge and unplug it from the power outlet.
2. Take a look at all the wire connections you can see between the freezer temperature sensor, main board, and compressor. If you find any loose connectors, make sure to reseat them.
3. Inspect the wiring for any cuts, damage, or other issues. Faulty connections can mess up the resistance measurements. Replace any damaged wiring you find.

If the wiring looks good, proceed to step 2.

Step 2 – Reset the power

1. Unplug the fridge or flip the breaker for about 30 seconds to reset the control board.
2. Restore power to the fridge and see if the ER FS message pops up again. If it does, chances are it’s not just a simple connection problem.

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Step 3 – Check the freezer sensor

1. Turn off the fridge and unplug it from the outlet.
2. Access the main board and find the wire connector CON7.
3. Disconnect the wire connection and find the freezer sensor wires at pins 17 & 18.
4. Set the multimeter to resistance (Ohms), which has a symbol that looks like this: Ω
5. Take the leads of the multimeter and touch them directly across the freezer sensor connector pins. Normal resistance is about 2.07K-2.54K Ω at room temperature. If the freezer is cooler than room temperature, the resistance can increase and the measurement range would depend on the specific temperature in the freezer section. If the resistance isn’t in this range and the freezer is at room temperature, then you’ve got a faulty sensor that needs to be replaced.

If the resistance is good, then there could be a problem with the control board.

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Step 4 – Check the control board

Plug the fridge in and turn it back on. To get into error code test mode, hold down the Ice Plus and Freezer buttons for 5 seconds. If ER FS comes up in test mode, it means the main control board needs to be replaced.

If the freezer sensor resistance checks out OK but the error persists in test mode, replace the main board.

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Final steps

1. Make sure the fridge is plugged in and turned on.
2. Allow the temperatures to stabilize. The ideal freezer temperature is 0°F. The fridge compartment should be 35-38°F.

READ MORE: Why Is My Refrigerator Not Cooling?

More information

Thank you for reading! We hope this guide helped you get your LG refrigerator working again.

If you have any other appliance repair needs or projects, don’t hesitate to explore our other troubleshooting guides and videos.

If you need replacement parts or some extra help with ordering them, grab your model number and head over to AppliancePartsPros.com, where you can chat with a pro, read our DIY blog and more. We can also help you troubleshoot common fridge problems here.

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