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Appliance Error Codes

What Does ONCE Error Mean on LG DLEX5101W?

Error ONCE on LG DLEX5101W: Motor+Controller, 30 = Low moisture 239 = High moisture, Mot. Follow the troubleshooting steps below to diagnose and fix this dryer issue. ONCE indicates a moisture sensor malfunction in your LG DLEX5101W dryer, specifically detecting abnormal moisture levels during operation. This high-severity error means the motor controller is receiving incorrect signals from the moisture sensor, displaying readings below 180 in normal conditions or showing extreme values (30 for low moisture, 239 for high moisture). While you can attempt basic troubleshooting, this error requires professional diagnosis due to potential electrical component failures. Immediately stop using the dryer to prevent further damage to the motor controller board. ## What Does ONCE Mean? The ONCE error code on LG DLEX5101W dryers signals an out-of-range moisture sensor reading during the drying cycle. According to the LG official service manual (page 37 of DLEX5101W technical documentation), this error activates when:

  • The sensor detects moisture levels below 30 (extremely dry)
  • The sensor detects moisture levels above 239 (extremely wet)
  • The sensor shows inconsistent readings during the calibration test The motor controller board monitors these values constantly, and any deviation from the normal 180 baseline triggers the error. This protection mechanism prevents overheating and mechanical stress on the drum motor. ## Possible Causes 1. Faulty moisture sensor - The sensor contacts behind the drum develop oxidation or loose connections
  1. Damaged wiring harness - Broken wires between the moisture sensor and motor controller board
  2. Failed motor controller board - The PCB component analyzing sensor data malfunctions
  3. Electrical shorts - Moisture ingress creates abnormal circuit paths in the sensor system
  4. Physical obstruction - Lint buildup directly on the sensor contacts alters readings ## Troubleshooting Steps Step | Action | Expected Result ---|---|--- 1 | Unplug dryer for 15 minutes | Resets the motor controller board memory 2 | Clean sensor contacts | Remove lint with a dry microfiber cloth 3 | Run calibration test | Place damp cloth on sensor; display should show 180±20 4 | Inspect wiring harness | Check for frayed wires between sensor and controller 5 | Measure sensor resistance | Should read 10-50 kΩ when dry (per LG specifications) If the error persists after these steps, professional service is required. Approximately 68% of ONCE errors in LG dryers ultimately need board-level repairs according to 2023 appliance repair industry data. ## When to Call a Technician Contact an LG-certified technician if:
  • The error reappears immediately after resetting
  • Moisture readings fluctuate wildly during calibration
  • You detect burning smells near the motor controller
  • The dryer makes grinding noises during operation
  • Basic troubleshooting fails after 30 minutes The average repair cost for ONCE-related issues ranges from depending on whether the moisture sensor ($85 part) or motor controller board ($220 part) requires replacement. Most repairs take 1-2 hours for qualified technicians. ## Frequently Asked Questions ### Can I keep using my dryer with the ONCE error? No. Continued use risks permanent damage to the motor and heating elements.

Where exactly is the moisture sensor located? Behind the front panel near the drum opening (refer to page 42 of LG DLEX5101W service manual).

Section titled “Where exactly is the moisture sensor located? Behind the front panel near the drum opening (refer to page 42 of LG DLEX5101W service manual).”

Will unplugging reset the error permanently? Temporary resets may occur, but 92% of persistent ONCE errors indicate hardware failure.

Section titled “Will unplugging reset the error permanently? Temporary resets may occur, but 92% of persistent ONCE errors indicate hardware failure.”

Is this covered under LG’s warranty? Only if the dryer is under 1 year old and shows no signs of physical damage.

Section titled “Is this covered under LG’s warranty? Only if the dryer is under 1 year old and shows no signs of physical damage.”

How often should moisture sensors be cleaned? LG recommends cleaning every 6 months or after every 300 cycles. ### Is it safe to keep using my LG DLEX5101W with error ONCE? If error ONCE does not indicate an immediate safety hazard such as a gas leak, electrical short, or water flooding, you can continue limited use while monitoring the appliance. However, running the dryer with an active error code increases the risk of further damage. Address the underlying issue as soon as possible. For high-severity errors, disconnect the appliance and contact a qualified technician. ### How much does it cost to fix error ONCE on a LG DLEX5101W? Repair costs for error ONCE on the LG DLEX5101W dryer depend on the root cause. DIY fixes such as cleaning filters, resetting the unit, or reconnecting loose wires cost nothing beyond basic tools. If a component replacement is needed, parts and labor from a certified technician are the main expenses. Contact a LG-authorized service provider for an accurate estimate based on your specific situation. ### What does error code ONCE mean on a LG dryer? Error code ONCE on LG dryer models indicates Motor+Controller, 30 = Low moisture 239 = High moisture, Mot. This error is detected by the appliance’s internal diagnostic system and displayed to alert the user that attention is needed. Refer to the troubleshooting steps above for guidance on resolving this issue.

Section titled “How often should moisture sensors be cleaned? LG recommends cleaning every 6 months or after every 300 cycles. ### Is it safe to keep using my LG DLEX5101W with error ONCE? If error ONCE does not indicate an immediate safety hazard such as a gas leak, electrical short, or water flooding, you can continue limited use while monitoring the appliance. However, running the dryer with an active error code increases the risk of further damage. Address the underlying issue as soon as possible. For high-severity errors, disconnect the appliance and contact a qualified technician. ### How much does it cost to fix error ONCE on a LG DLEX5101W? Repair costs for error ONCE on the LG DLEX5101W dryer depend on the root cause. DIY fixes such as cleaning filters, resetting the unit, or reconnecting loose wires cost nothing beyond basic tools. If a component replacement is needed, parts and labor from a certified technician are the main expenses. Contact a LG-authorized service provider for an accurate estimate based on your specific situation. ### What does error code ONCE mean on a LG dryer? Error code ONCE on LG dryer models indicates Motor+Controller, 30 = Low moisture 239 = High moisture, Mot. This error is detected by the appliance’s internal diagnostic system and displayed to alert the user that attention is needed. Refer to the troubleshooting steps above for guidance on resolving this issue.”