Dehumidifier displays E7 and stops operating after a short time

Safety: Unplug the unit before opening the control panel.

Steps:

• Extended reset: Unplug the dehumidifier for at least 30 minutes to allow capacitors to discharge and the microcontroller to fully reset. Plug back in and test.
• Check power quality: Plug the unit directly into a wall outlet (no extension cords or power strips). Avoid outlets with known flicker or brownouts.
• Inspect control connections: Remove the top/control panel cover. Locate the ribbon cable or harness between the display PCB and the main control board. Ensure both ends are fully seated and not corroded.
• Look for damage: Examine both boards for burn marks, swollen components, or signs of moisture intrusion.
• Reseat connectors: Carefully unplug and replug the display harness and any other low-voltage connectors to clear minor oxidation.
• Surge protection: If the error clears, consider using a surge protector to prevent future memory corruption from power spikes.
• Board replacement: If E7 persists, the main control board or display board may be defective. Replacement typically involves swapping the entire board assembly and is best done by a technician or experienced DIYer following the service manual.