Daewoo Microwave Error Code ERROR 3

ERROR 3 indicates that the microwave's control board has detected a fault in the thermistor or one of the heater elements during convection or grill operation. The thermistor may be reading 0 ohms (shorted) or infinite resistance (open) instead of the normal 100K to 1000K ohm range. Alternatively, one of the heater elements, convection, upper grill, or lower, may have lost continuity. The appliance shuts down to prevent unsafe operation.

No. ERROR 3 means the microwave has detected a failure in its temperature monitoring or heating system and has stopped operation for safety reasons. Attempting to bypass or ignore the error and continue using the appliance in convection or grill mode could result in uncontrolled heating or fire risk. The fault should be diagnosed and repaired before the unit is used again.

Unplugging the microwave and restoring power may temporarily clear the error display, but ERROR 3 will return as soon as the appliance attempts convection or grill operation and re-detects the fault. A reset does not repair a failed thermistor or burned-out heater element. The underlying component failure must be identified and corrected to permanently resolve the error.

A knowledgeable DIYer with a multimeter can perform the diagnostic steps: check the thermistor resistance and test each heater element for continuity. If a specific component is confirmed faulty, replacing a thermistor or a heater element is a manageable repair. However, microwave capacitors store lethal voltage even when the unit is unplugged, so the high-voltage capacitor must be safely discharged before working inside the appliance.

Repair costs depend on which component has failed. A replacement thermistor is generally an inexpensive part, typically in the range of a few dollars to around twenty dollars. A heater element replacement can cost more, often in the range of thirty to eighty dollars for parts, with additional labor costs if a technician is hired. If the control board is the root cause, repair costs rise significantly and may approach the cost of replacing the appliance.