LG Microwave Error Code E-04

E-04 on an LG microwave indicates a cooking time over-limit error in Convection mode. The appliance enforces a maximum cook time of 45 minutes for Convection operation, and this code appears when a longer time is entered. It is not a hardware fault; it is the control system rejecting an out-of-range input.

Yes, E-04 is a non-critical input validation error and does not indicate any damage to the appliance. The microwave simply prevents the invalid cycle from starting. After pressing Cancel and correcting the time entry, the oven is safe to use normally.

If the error is caused by a simple over-limit time entry, there is no repair cost involved. If a faulty touchpad or membrane switch is responsible, touchpad replacement parts typically range from $20 to $80 depending on the model, plus labor if a technician is used. A main control board replacement, if needed, can range from $60 to $150 or more for parts alone.

Press the Cancel key to clear the error and exit the current state. Once cleared, re-enter your desired Convection cook time making sure it does not exceed 45 minutes. If the error reappears without an obvious over-limit entry, inspect the touchpad for stuck keys or contact a technician to evaluate the control panel.

Pressing the Cancel key is the recommended reset action and is sufficient to clear E-04 in most cases. You can also unplug the microwave for 60 seconds to perform a full power reset. However, the error will return if the same over-limit time is entered again in Convection mode.