LG Washer Error Code tC — What It Means & How to Fix It

What Does This Error Mean?

The tC error means your LG washer has a thermistor (temperature sensor) circuit problem. The sensor that reads water temperature is faulty. The washer may stop mid-cycle to avoid overheating.

Affected Models

WM3900HWA
WM4000HWA
WM5000HVA
Most LG front-load washers

Common Causes

Thermistor (NTC temperature sensor) is faulty or out of range
Loose or corroded wiring connection to the thermistor
Water temperature is extremely cold causing a false reading
Heater assembly problem affecting sensor readings
Main control board not reading the sensor signal correctly

How to Fix It

Unplug the washer and wait 60 seconds.

Cold inlet water can sometimes trigger a false tC reading. Let it warm slightly.
Check that the hot water supply tap is fully open.

If the incoming water is extremely cold, the sensor may read out of range.
Plug the washer back in and run a warm water cycle.

If the error clears and the cycle runs normally, it was a temporary temperature issue.
If tC returns consistently, the thermistor needs testing.

A technician can test it with a multimeter. A faulty thermistor shows an incorrect resistance reading.
Replace the thermistor if confirmed faulty.

This is an inexpensive part — usually under $30. Labor adds to the cost.

When to Call a Professional

Thermistor replacement is a low-cost repair. But confirming it's actually the sensor (not the board) requires a multimeter test. Expect repair costs of $80–$200 including parts and labor. Contact LG support or a certified technician.

Frequently Asked Questions

What is the difference between tC and tE on an LG washer?

Both relate to the temperature sensor. tE means the thermistor reading is completely out of range. tC means there's a circuit-level fault — possibly wiring or the sensor itself.

Can cold weather cause the tC error on an LG washer?

Yes. If the washer is in a very cold space like a garage — the water temperature can trigger a false reading. Bring the room temperature above 50°F (10°C) if possible. This often resolves temperature-related sensor errors.

How much does a thermistor cost for an LG washer?

The thermistor part itself typically costs $15–$40. With professional diagnosis and labor, total repair is $80–$200. It's one of the more affordable appliance repairs.