LG Microwave Error Code E-b1

E-b1 indicates a cooling fan motor PCB temperature sensor open error. The microwave's control board has detected an open circuit in the temperature sensor that monitors the cooling fan's circuit board. This means the sensor is either disconnected, has a broken wire, or has failed internally. The microwave halts operation because it cannot confirm safe thermal conditions without a valid sensor signal.

No, you should not attempt to operate the microwave while E-b1 is active. This error indicates the cooling system's temperature monitoring is non-functional, meaning the microwave cannot protect itself from overheating during a cooking cycle. Continued use without a working thermal sensor could cause damage to internal components or create a fire hazard.

If the fix is simply reseating a loose connector, there is no parts cost and the repair can be done at home. If the temperature sensor needs replacement, parts typically range from around $10 to $40 depending on the model. If a professional repair technician is needed, expect to pay a service call fee plus labor, which can bring the total to somewhere between $80 and $200 or more depending on your location and the extent of the repair.

Start by unplugging the microwave and locating the temperature sensor connector on the cooling fan motor PCB, then firmly reseat the connector. If the error returns after power is restored, test the sensor for continuity to determine if it has failed internally and needs replacement. Inspect the wiring harness for any visible damage as well. If the sensor and wiring are both good, the PCB may require further diagnosis or replacement.

A power reset by unplugging the unit for a few minutes may temporarily clear the error display, but the code will return if the underlying cause has not been corrected. The open circuit condition in the temperature sensor must be physically resolved, either by reseating the connector or replacing the faulty component, before the error will stay cleared.