Freezer shows E5 and may shut down or fail to maintain set temperature, often after a power event.

Safety: Disconnect power before removing any access panels or touching the control board.

Steps to address E5:

• Power cycle: Unplug the freezer for at least 10 minutes to allow capacitors to discharge. Plug it back in and check if E5 clears.
• Check power quality: Ensure the freezer is plugged directly into a properly grounded outlet (no extension cords). Verify voltage is stable (typically 110–120 V in North America).
• Access the control board: Remove the rear lower metal cover to expose the main PCB. Take a photo of wiring for reference.
• Inspect the board: Look for burnt components, bulging capacitors, or signs of moisture. Check that all connectors are fully seated.
• Reseat connectors: One by one, unplug and firmly replug each harness to clean contacts. Do not bend pins.
• Try a reset: Some Costway models have a small reset button on the control board or behind the display panel. Press and hold for 3–5 seconds with power applied (if the manual specifies this).
• Replace the control board if needed: If E5 persists and the freezer does not operate correctly, the main PCB is likely faulty. Replace it with the exact Costway freezer control board model, transferring each connector to the same position.

Warning: Board-level repairs (soldering components) should be done only by qualified technicians.