Samsung Air Conditioner Error Code E104

E104 indicates a communication error between the outdoor unit's Main PCB and its Inverter PCB. The system detected a loss of signal between these two boards for at least one minute before logging the fault and shutting down. The problem is located inside the outdoor unit and typically involves the wiring harness or one of the two control boards.

No. When E104 is active, the system has already shut down operation to protect the compressor and inverter components. Attempting to force the unit to run without resolving the communication fault could result in uncontrolled compressor behavior or further board damage. The unit should remain off until the underlying fault is diagnosed and corrected.

Repair costs vary depending on the root cause. If the issue is only a loose or corroded connector, a service call fee of roughly 75 to 150 dollars may be the primary expense. If a PCB replacement is needed, costs typically range from 200 to 600 dollars or more depending on the specific board and labor rates in your area. Getting a diagnostic visit before committing to parts replacement is advisable.

A knowledgeable DIYer can safely inspect the outdoor unit's wiring harness for loose connectors or visible damage, which is the most common cause of this error. However, testing or replacing the Main PCB or Inverter PCB requires familiarity with electrical diagnostics and handling of high-voltage components inside the outdoor unit. If wiring inspection does not resolve the issue, a licensed technician should complete the repair.

A power reset may temporarily clear the displayed code, but if the underlying wiring or board fault still exists, the error will return within a minute of the system attempting to restart. The one-minute detection window means the fault will reappear quickly if the root cause is not addressed. A reset is only useful for confirming whether the fault is intermittent or persistent.