Controller buttons are unresponsive or stick; difficult to change modes or settings.

Safety first: Place the controller in OFF and open the main breaker. Disconnect battery before disassembling the panel.

• Clean panel surface: Wipe the keypad with a slightly damp cloth to remove dirt and grime. Do not use solvents.
• Inspect for moisture: Check inside the panel for signs of water intrusion and dry thoroughly.
• Keypad replacement: If buttons remain unresponsive, replace the membrane keypad or entire controller front panel assembly per Guardian instructions.