Display shows LOC or a lock icon and buttons do not respond

This is usually a user setting, not a hardware fault.

• Unlock sequence: On most Artesian topsides, press and hold the Temperature Up and Temperature Down buttons together for 3–5 seconds to unlock. If that fails, consult the specific Artesian model manual for the lock/unlock combination.
• Power cycle: Turn the GFCI breaker off for 30 seconds and back on. If LOC returns immediately, the lock setting is stored and must be cleared via the keypad sequence.
• Check for stuck buttons: Inspect the keypad for physical damage or buttons that do not spring back. Moisture intrusion can cause phantom button presses and lockouts.

If the panel will not unlock or some buttons do not respond, the topside control panel may need replacement.