Whirlpool Microwave Error Code ERR 0

ERR 0 on a Whirlpool microwave indicates a fault in the convection temperature sensor circuit. This sensor, typically a negative temperature coefficient (NTC) thermistor, monitors the oven cavity temperature during convection cooking cycles. The control board continuously reads the resistance value from this sensor to regulate heating element output. When the board detects a resistance reading that falls outside the expected range, either because the sensor circuit is open (not connected) or shorted, it throws ERR 0 and halts convection operation to prevent overheating or inaccurate temperature control.

The two root causes spelled out in the error definition are an open circuit and a short circuit. An open circuit occurs when the sensor is physically disconnected, the wiring harness connector has pulled loose, or an internal wire has broken. A short circuit occurs when the sensor element itself has failed internally, or when wiring insulation has worn through and two conductors are making unintended contact. Both conditions produce abnormal resistance readings at the control board input, triggering the fault.

Diagnosis begins at the sensor connection point. A technician should inspect the harness connector at the sensor and at the control board for corrosion, bent pins, or loose seating. If connections are secure, the sensor itself should be tested with a multimeter for continuity and resistance. A shorted sensor will typically read near zero ohms, while an open sensor will read infinite resistance. Either reading confirms the sensor requires replacement.