rE
LG Washing Machine
Severity: CriticalWhat Does This Error Mean?
The rE error on an LG washer indicates a relay error in the main control board. A relay is an electrical switch on the control board that turns components like the motor, heater, or pump on and off. When a relay fails, the board cannot properly control one of these components. This usually requires professional diagnosis and may mean control board replacement.
Affected Models
- WM3900HWA
- WM4500HBA
- WM3500CW
- WM2650HRA
- Various LG front-load washer models
Common Causes
- Failed relay on the main control board — the relay has burned out or stuck
- Power surge that damaged relay components on the board
- Age-related failure of relay components, especially on washers over 7 years old
- Short circuit in a component like the motor or heater causing relay damage
- Loose wiring harness connection to the main control board
How to Fix It
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Unplug the washer for 10 full minutes and plug it back in. Control board errors sometimes clear with a hard reset, especially if caused by a power spike. Attempt to start a cycle and see if the error returns.
If the error does not return after a reset, monitor the washer for a few cycles. A one-time glitch may not recur.
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Check that the washer is plugged directly into a wall outlet — not a power strip or extension cord. Also check that the outlet is on a properly sized circuit. Voltage instability can cause control board issues including relay faults.
LG washers require a grounded 120V, 15-amp or 20-amp outlet depending on the model.
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Inspect all wiring harness connectors on the main control board. A loose connector can cause erratic board behavior including relay errors. With the machine unplugged, open the back or top panel and gently press each connector to ensure it is firmly seated.
Only do this if you are comfortable working with electrical appliances. If not, call a technician.
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If the error returns after resetting, have a technician use an LG-compatible service tool to read the specific fault sub-code. The rE error has sub-types that indicate which relay or which circuit has failed. This guides the repair.
Attempting to replace the control board without confirming the fault sub-code risks replacing the wrong component.
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If the main control board is confirmed faulty, replacement is the typical fix. Boards can sometimes be repaired by electronics specialists for less than the cost of a new board — search for appliance control board repair services in your area.
Some third-party services will repair and return your board by mail for $100–$150, cheaper than a new board.
When to Call a Professional
An rE error almost always requires professional diagnosis. Control board replacement costs $200–$400 for the part, plus $100–$200 labor. Before replacing the board, have a technician confirm the relay is the issue — not a shorted downstream component like the motor.
Frequently Asked Questions
What is a relay on a washing machine control board?
A relay is like an electrically controlled switch. The control board uses small relay switches to turn high-voltage components on and off — like the motor, the heater, and the pump. When the board sends a signal to start the motor, a relay closes to allow current to flow. When the relay fails, the board can no longer control that component.
Can I keep using my washer with an rE error?
It depends on what the relay controls. If a motor relay failed, the washer will not run at all. If a heater relay failed, the washer may run cold. Either way, continuing to operate with a failed relay risks damaging other board components. Get it diagnosed promptly.
How long do LG washer control boards last?
Typically 8–12 years under normal use. Power surges, voltage fluctuations, and excessive heat in the laundry area can shorten board life. If your washer is under 5 years old and the board has failed, check if it is still under LG's limited warranty — LG offers a 1-year parts and labor warranty and sometimes longer on the motor.