LG ThinQ AC CH46 Error: Suction Line Thermistor Fault... | digitalhomefaults.org

Technical Background:

The CH46 error code indicates a fault within the suction line thermistor circuit. This thermistor measures the temperature of the refrigerant gas returning to the compressor. The AC's control board uses this temperature to optimize compressor operation and prevent damage. The thermistor presents a variable resistance to the control board, with resistance changing based on temperature. A short circuit condition implies a low resistance reading, often triggering the CH46 error. The system comprises the thermistor, wiring harness, and the main control board. Wireless communication (Wi-Fi 2.4GHz) enables remote monitoring and control via the ThinQ app, reporting error status.

Symptoms:

The LG ThinQ AC unit displays error code CH46 on the unit's display panel or within the ThinQ app. The unit may cease cooling operation entirely or exhibit reduced cooling performance. LED indicator lights may blink in a repeating sequence (refer to the LG service manual for specific patterns).

Possible Causes:

Damaged or shorted suction line thermistor.
Wiring harness damage, leading to a short circuit in the thermistor circuit.
Corrosion on the thermistor connector pins, affecting resistance readings.
Moisture ingress into the thermistor housing or wiring, creating a short.
Faulty main control board, providing incorrect voltage to the thermistor or misinterpreting readings.
Extreme ambient temperature fluctuations outside operational range, particularly in Canadian winter conditions (-40°C).

Solution:

1

Disconnect power to the AC unit at the breaker (240V). Verify power is off with a non-contact voltage tester.
2

Locate the suction line thermistor (refer to the LG service manual for its exact location within the AC unit).
3

Visually inspect the thermistor and its wiring for any signs of damage, corrosion, or moisture.
4

Disconnect the thermistor from the control board. Use a digital multimeter to measure the resistance across the thermistor terminals. A reading close to zero ohms indicates a short circuit.
5

Check the wiring harness for continuity and shorts to ground using a multimeter.
6

If the thermistor is shorted, replace it with a new, OEM-approved thermistor.
7

Reconnect the wiring and power, then test the unit's operation. Clear the error code via the ThinQ app or service menu.

Safety Warning:

Disconnecting power at the breaker is crucial to prevent electrical shock. Never work on live circuits. Ensure the AC unit is properly grounded. Incorrect wiring can damage the unit and create a fire hazard. Only qualified technicians should perform repairs involving refrigerant lines.

Prevention:

- Perform regular visual inspections of the AC unit, looking for signs of damage or corrosion, especially after Canadian winters. - Ensure proper drainage to prevent moisture buildup around the unit. - Periodically check the thermistor wiring for secure connections. - Apply dielectric grease to connector pins to prevent corrosion. - Keep the AC unit clean and free from debris that could trap moisture.

Expert Tip:

Access the LG service menu by pressing and holding the "Filter Reset" button for 5 seconds. This allows you to directly read the thermistor's resistance value in real-time and perform advanced diagnostics without the ThinQ app. Some LG units also have a built-in self-test diagnostic routine accessible through the remote control.

Frequently Asked Questions

•How do I locate the suction line thermistor in my LG ThinQ AC unit?

Refer to the service manual specific to your LG ThinQ AC model. It contains detailed diagrams showing the location of all components, including the suction line thermistor.

•Where can I purchase a replacement suction line thermistor for my LG ThinQ AC unit?

Authorized LG appliance parts distributors are the best source for OEM-approved thermistors. Online retailers specializing in appliance parts are also an option, but verify the part's authenticity and compatibility before purchasing.

•What is the typical resistance range of a healthy suction line thermistor at room temperature?

The resistance value varies depending on the specific thermistor model. However, at room temperature (approximately 25°C), expect a resistance value between 5kΩ and 10kΩ. Refer to the service manual for your specific thermistor's datasheet.

LG ThinQ AC CH46 Error: Suction Line Thermistor Fault Diagnosis

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

Frequently Asked Questions

•How do I locate the suction line thermistor in my LG ThinQ AC unit?

•Where can I purchase a replacement suction line thermistor for my LG ThinQ AC unit?

•What is the typical resistance range of a healthy suction line thermistor at room temperature?

Related Questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: