Display shows LOC or LOCK; buttons on the topside control are unresponsive.

Safety: No electrical work is required for this procedure.

• Step 1 – Unlock sequence: Refer to your Catalina user manual. Commonly, pressing and holding specific buttons (e.g., Temp Up + Temp Down for 3–5 seconds) will toggle the lock.
• Step 2 – Power reset: If the unlock sequence fails, turn off power at the breaker for 30 seconds and restore. Try the unlock sequence again.
• Step 3 – Check for stuck keys: Inspect the topside panel for physical damage, moisture under the overlay, or keys that do not spring back. A stuck key can keep the panel in a locked state.
• Step 4 – Replace panel if needed: If LOC remains and buttons are unreliable, replace the Catalina-compatible topside control panel.