KitchenAid Microwave Error Code F4E3

F4E3 indicates a hood NTC thermistor failure. The HF NTC thermistor is a temperature sensor in the hood or vent area of the microwave, and this code appears when the control board determines its reading is inaccurate or out of range. Entering Diagnostics mode and checking the HF NTC sensor temperature under Component Activation is the recommended first step to confirm the fault.

It is generally not recommended to continue using the microwave while an active fault code is present. The HF NTC thermistor monitors hood temperatures, and without a functioning sensor the control board cannot properly track thermal conditions in that area. Continuing to operate the unit could potentially allow an overheating condition to go undetected.

Repair costs depend on whether the issue is a failed thermistor, damaged wiring, or a faulty control board. A thermistor replacement is typically the least expensive fix, with parts generally ranging from $15 to $50 and professional labor adding $75 to $150 or more depending on your location. A control board replacement, if required, would cost significantly more in both parts and labor.

A knowledgeable DIYer can diagnose this fault by using the microwave's built-in Diagnostics mode to check the HF NTC sensor temperature reading against actual room temperature. If the reading is clearly wrong and wiring connections appear intact, replacing the HF NTC thermistor is the typical repair. Keep in mind that microwave capacitors retain a dangerous charge even when unplugged, so only those comfortable working around high-voltage components should attempt internal repairs.

A power reset by unplugging the unit or cutting power at the circuit breaker may temporarily clear the error code, but if the thermistor or its wiring has actually failed the code will return. A reset alone does not fix the underlying hardware problem. Proper diagnosis through Diagnostics mode is needed to determine whether a component must be replaced.