Door will not open fully; it stops short of the usual open position without any error code.

Safety first: Keep clear of the door path while adjusting.

• Check for obstructions: Inspect the area above the door and near the header for pipes, beams, or brackets limiting travel.
• Adjust UP limit: Use the Merlin control panel or limit screws to increase the open travel slightly. Test after each adjustment.
• Inspect top panel and arm: Ensure the opener arm is not binding or hitting the door track or ceiling. Reposition the header bracket if necessary.
• Run full cycle: Confirm the door opens fully without hitting anything and closes properly.