LG Microwave Error Code F5

The F5 error code on an LG microwave means the control board detected that the oven cavity temperature was too high at the moment a cooking cycle was started. It is a protective fault that prevents the magnetron from operating in an already-overheated cavity. In most cases, the fix is simply allowing the unit to cool down before attempting to use it again.

The F5 code is actually the microwave's safety system working correctly by refusing to operate when it detects excess heat. You should not attempt to force the unit to run while this code is displayed. Wait for the cavity to cool, and if the error clears on its own, the microwave is safe to use normally. If the error appears repeatedly or does not clear after cooling, have the unit inspected before continued use.

If the issue is simply an overheated cavity, there is no repair cost at all since waiting for the unit to cool resolves the problem. If a cavity temperature sensor needs to be replaced, parts and labor costs typically range from around $75 to $200 depending on the service provider and part availability. If the main control board is at fault, repair costs can range from $150 to $350 or more, at which point comparing the repair cost to the cost of a replacement unit is worth considering.

Start by opening the microwave door and letting the cavity cool to room temperature, which typically takes 10 to 20 minutes. Once cooled, close the door and try starting a cycle again. If the error persists after the unit is fully cooled, check that the vents are not blocked, and if the problem continues, the cavity temperature sensor or its wiring may need to be inspected and potentially replaced.

A power reset by unplugging the unit for a few minutes may clear the code from the display, but if the underlying cause is an actually high cavity temperature, the code will return as soon as you try to start a cook cycle. The only lasting fix for a heat-related F5 is to let the cavity cool fully. If the code reappears even after the microwave is cold, a component fault such as a bad sensor is the likely cause and the reset will not resolve it.