The LG dishwasher F35 error code signals a problem with the heated air temperature sensor, also known as a thermistor. This sensor is crucial for monitoring the air temperature during the drying cycle. A faulty sensor can prevent the dishwasher from drying dishes effectively or cause other issues. This guide provides a step-by-step troubleshooting process to help you diagnose and resolve the F35 error.
Understanding the LG dishwasher F35 error code:
The LG dishwasher F35 error code indicates that the control board is receiving an out-of-range reading from the heated air temperature sensor. This could be due to a faulty sensor, wiring issues, a problem with the heater itself, or a malfunctioning control board.
Solving the LG dishwasher F35 error code: Troubleshooting Steps:
This troubleshooting process is presented as a series of questions and actions:
- Is the F35 error displayed?
- Yes: Proceed to the next step.
- No: The issue is not related to the heated air temperature sensor.
- Are the thermistor and heater connectors properly connected?
- No: Check all wire harness connections, especially at the thermistor and heater. Ensure they are securely connected and free from corrosion or damage. Replace the wire harness if necessary.
- Yes: Proceed to the next step.
- Does the thermistor measure proper resistance? (8kΩ-44kΩ, approximately 12.7 kΩ at 70°F/21°C)
- No: Replace the thermistor. This indicates a faulty sensor.
- Yes: Proceed to the next step.
- Does the main board produce 120 volts of AC on the heater connector?
- No: Replace the main board. This indicates a problem with the control board’s ability to power the heater.
- Yes: Proceed to the next step.
- Check the heater for proper resistance (11–13 ohms).
- No: Replace the heater. This indicates a faulty heating element.
- Yes: This is a less common scenario, but it’s possible there is an intermittent wiring issue, or a problem with the control board that is not related to voltage output. Inspect all wiring thoroughly and consider control board replacement if wiring is sound.
Electrical Testing Details:
If you’re comfortable with electrical testing, you can use a multimeter to check the resistance of the thermistor and heater, and the voltage to the heater. Here’s a breakdown of the typical wiring (note: always refer to your dishwasher’s specific wiring diagram as colors may vary):
Air Dry Thermistor Check:
- Red Wire to Black Wire: Measure resistance. The reading should be between 8kΩ and 44kΩ. A typical value is around 12.7 kΩ at room temperature (70°F/21°C).
Air Dry Heater Check:
- Yellow Wire to White Wire: Measure resistance. The reading should be between 11Ω and 13Ω.
- Heater Voltage Check: With the dishwasher attempting to dry, carefully measure the AC voltage between the yellow and white wires. You should measure approximately 120V AC. Exercise extreme caution when measuring live voltage.
Important Notes:
- Safety First: Always disconnect power to the dishwasher before performing any electrical testing or repairs.
- Wiring Diagrams: Refer to the wiring diagram for your specific LG dishwasher model. Wiring colors and connector configurations can vary significantly.
- Thermistor Resistance and Temperature: The thermistor’s resistance changes with temperature. The provided 12.7 kΩ value is an approximation at room temperature.
LG dishwasher F35 error code: Summary Table
| Condition | Action | Possible Cause |
|---|---|---|
| F35 Error Displayed | Proceed to next step | Heated Air Temperature Sensor Problem |
| Thermistor/Heater Connectors Not Connected | Check/Reconnect the wiring harness; replace if needed | Loose or Damaged Wiring/Connections |
| Thermistor Resistance Out of Range | Replace Thermistor | Faulty Thermistor |
| Main Board Not Producing 120V AC on Heater Connector | Replace Main Board | Faulty Control Board (Heater Circuit) |
| Heater Resistance Out of Range | Replace Heater | Faulty Heater Element |
| All Tests Pass | Thoroughly Inspect Wiring for Intermittent Issues, Consider Control Board | Intermittent Wiring Issue, Potentially a Control Board Issue |
Mike Walker is an appliance repair technician with 15 years of experience dedicated to helping homeowners understand and fix their appliances. On this site, I break down complex error codes and offer easy-to-follow troubleshooting solutions.
