F9 appears and the spa may not respond to keypad inputs or may reboot repeatedly.

Safety first: Turn off power at the breaker before removing the topside panel or opening the control box.

• Inspect keypad cable: Access the underside of the topside control panel and trace the ribbon cable to the control pack. Unplug and replug the connector to ensure a solid connection.
• Check for moisture: Look for condensation or water under the topside panel. Dry thoroughly and reseal the panel with appropriate gasket or silicone if necessary.
• Visual inspection: Examine the ribbon cable for kinks, cuts, or corrosion on the contacts. Replace the cable or entire keypad if damaged.
• Test with replacement keypad: If available, connect a known-good Aquavia Spa topside panel. If F9 clears, the original keypad is faulty. If not, the control board interface may be defective and require replacement.