Troubleshooting error code 01 on an LG air conditioner
Steven E / Tuesday April 1, 2025
Is your LG air conditioner displaying error code 01? Don’t worry, this is a problem that you can fix yourself without the need for a costly service call, and we’re here to help!
If you find out that you need any replacement parts for your appliance while you’re troubleshooting, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.
The troubleshooting information provided in this article 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.
What the error code means
The error code 01 on an LG multi-split air conditioner indicates an issue with the indoor unit’s return air thermistor.
The return air thermistor is responsible for measuring the temperature of the air returning from the conditioned space back to the indoor unit. This temperature information is needed for the unit’s control system to regulate the cooling or heating operation by cycling the compressor on or off to maintain the desired indoor temperature.
Safety precautions
When working on any appliance, remember to keep safety first. Here are some 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 injury from electric shock.
- Wear insulated work gloves to protect your hands from sharp metal parts, pinching hazards and debris.
- 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 the interior parts.
- Clear your workspace of clutter and other obstacles. Keep children and pets away from the work area.
- Never work on internal parts with bare wet hands. Make sure the work area is completely dry.
- Check your user manual to see if there are specific installation or safety instructions for your part or appliance.
- Be gentle when handling or removing parts. Excessive force might damage the appliance or cause injury.
- Wear safety glasses when working with chemicals, dust or cleaning large debris to prevent injury.
- If the appliance has recently been used, give it plenty of time for any heating parts to cool down before working on it.
- Take pictures or make a note of wiring terminals or other connections before disconnecting to prevent any problems with reassembly.
- 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.
Tools and materials needed
- Multimeter
- Screwdrivers
Important: The specific tools required may vary depending on the model of your appliance and the type of fasteners used on it. Always consult the user manual or refer to any specific instructions provided by the manufacturer for the recommended tools for your appliance model.
Troubleshooting steps
- Locate the indoor unit’s return air thermistor, which is connected to the indoor unit’s main control board (PCB).
- Gently disconnect the return air thermistor from the main control board. It is usually connected via a small connector, so take care to release it without damaging the wiring or PCB.
- Set your multimeter to the resistance (ohm) measurement mode.
- Place the multimeter’s probes on the two terminals of the thermistor.
- At a temperature of around 70°F (21°C), the resistance should be in the range of 10-12k ohms.
- Suppose the thermistor is exposed to a significantly different temperature. In that case, the resistance value will vary, but it should still fall within the acceptable range of 10-12k ohms when at normal room temperature.
- If the resistance is outside the expected range, the thermistor is faulty and needs to be replaced. A malfunctioning thermistor may provide incorrect temperature readings, leading to errors or improper operation of the air conditioner.
- If the resistance is within the normal range: The thermistor is likely functioning properly. In this case, the issue may lie with the main control board, and it will need to be replaced to resolve the error code 01.
Next steps:
- If the thermistor is faulty, proceed with purchasing a replacement part and installing it.
- If the thermistor is working correctly, you will need to replace the main control board (PCB) since the error is likely related to the board’s malfunction or failure.
Additional information
Thank you for reading! We hope this guide helped you get your LG multi split air conditioner 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.
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Keep reading:
How to get better air quality from your window air conditioner
How to Clean Your Air Conditioner the Easy Way
What is a Ductless Mini-Split Air Conditioner And How Does it Work?
With nearly a decade of experience in providing top-notch customer service regarding appliance parts and repair, Steven enjoys sharing practical advice, troubleshooting tips, and interesting information to help readers stay informed.