The display shows 'LOC' or 'LOCK'; settings cannot be changed, and some functions are disabled.

Safety: No electrical work is required for this procedure.

• Unlock keypad: Press and hold the designated 'LOCK' or 'MODE' button combination (refer to the Fafco manual) for several seconds until 'LOC' disappears.
• Check installer lock: Some models have an installer-only lock in the setup menu. Enter the installer code if known, or perform a factory reset if permitted.
• Power-cycle: Turn the controller off and back on. If 'LOC' appears immediately without pressing buttons, the keypad may be shorted.
• Inspect keypad: Look for moisture or physical damage around the buttons. If the keypad membrane is compromised, the front panel may need replacement.