LG Microwave Error Code F3

The F3 code on an LG microwave means the control board has detected a key on the panel that appears to have been continuously activated for more than 60 seconds. This triggers a fault to prevent the microwave from operating unintentionally. The cause is usually a damaged or contaminated touchpad membrane, though the control board can also be responsible.

Unplugging the microwave for several minutes and plugging it back in may temporarily clear the F3 code, but the error will return if the underlying fault is not corrected. A reset does not repair a shorted or damaged touchpad, it only clears the stored fault from the control board. A permanent fix requires identifying and correcting the shorted key condition.

Repair costs vary depending on the failed component. A replacement touchpad membrane typically ranges from $20 to $80 for the part, with additional labor costs if a technician performs the work. If the main control board is at fault, parts alone can range from $60 to $180 or more. Given these costs, it is worth comparing the repair estimate to the current value of the microwave before proceeding.

In some cases, yes. Start by unplugging the microwave and carefully cleaning the control panel surface to remove any moisture, grease, or debris that might be pressing against a key. If the error returns after power is restored, the touchpad membrane likely needs to be replaced, which is a repair many DIYers can perform with basic tools and the correct replacement part. If replacing the touchpad does not resolve the code, a faulty control board may require professional diagnosis.

No, you should not attempt to use the microwave while the F3 error is active. The fault indicates a stuck or shorted key input, which could lead to unintended operation or prevent the microwave from responding correctly to controls. Unplug the unit until the issue is properly diagnosed and repaired.