LG Microwave Error Code S-01

S-01 is an Over Time Error indicating the microwave has operated continuously beyond the maximum allowed run time for the detected internal temperature. LG microwaves use thermal protection logic that ties allowable cooking duration to internal temperature levels. When the appliance exceeds the cutoff time for the current temperature, it shuts down and displays S-01 to prevent heat damage.

The S-01 error is a built-in safety shutoff, so the appliance is doing exactly what it is designed to do. Once the unit has cooled down completely, it is generally safe to resume use. However, if the error occurs repeatedly during short or normal cooking sessions, stop using the microwave and have it inspected, as a failed cooling fan or faulty sensor could allow unsafe heat buildup.

If the error is caused only by extended use or a ventilation issue, there is no parts cost involved. If a cooling fan replacement is needed, parts and labor typically range from $75 to $175 depending on the model and service provider. A faulty thermal sensor is generally a lower-cost repair, with parts and labor often ranging from $50 to $130.

Start by turning the microwave off and allowing it to cool fully before attempting to use it again. Once cooled, check that all ventilation openings are unobstructed and that the unit has adequate clearance around it. If the error returns after normal-length cooking cycles with good airflow, the cooling fan or a thermal sensor may need to be inspected and potentially replaced.

Turning the microwave off and allowing it to cool sufficiently is the primary reset procedure for S-01. Once the internal temperature drops to a safe level, the error should clear and normal operation can resume. If the error reappears immediately or during short cooking cycles, simply resetting will not resolve the underlying cause and further diagnosis is needed.