KitchenAid Microwave Error Code F3H

F3H indicates that the humidity sensor has reported a value outside of its expected operating range. The humidity sensor monitors steam during cooking to enable automatic sensor-cook functions. The code points to either a faulty sensor or a failed electronic control board. Power must be disconnected before diagnosing the issue.

The F3H fault will disable sensor-based cooking functions, so automatic moisture-sensing cook modes will not operate correctly. Basic timed cooking may still function depending on how the control responds to the fault, but using the appliance in a fault state is not recommended. Disconnect power and address the issue before resuming regular use.

Disconnecting power temporarily may clear the code from the display, but if the underlying component, either the humidity sensor or the electronic control board, has actually failed, the F3H error will return once power is restored and a sensor-cook cycle is attempted. A permanent fix requires replacing the faulty component rather than simply resetting the appliance.

A knowledgeable DIYer can attempt this repair by first disconnecting power, then connecting a replacement humidity sensor to the electronic control at connector P1 and restoring power to see if the code clears. If the new sensor resolves the error, only the sensor needs replacement. If the code persists, the electronic control board must be replaced, which is a more involved repair.

If only the humidity sensor needs replacement, parts typically range from around $20 to $60 depending on the model, plus labor if a technician performs the work. If the electronic control board is the failed component, parts alone can range from $80 to $200 or more. A professional diagnosis and repair, including labor, could range from $100 to $300 or higher depending on the required parts.