Door will not fully close; opener stops and reverses at about the same point each time; display shows “4”.

Safety first: Keep the door area clear while adjusting travel limits. Use a stable ladder to access the opener head.

• Locate limit controls: On most Marantec units, travel limits are set via electronic buttons or dials on the head. Refer to the label on the cover or the manual for the exact procedure.
• Reset down limit: Enter programming mode (often by pressing and holding the “P” or “Program” button until the display changes). Use the up/down buttons to move the door to the fully closed position, ensuring the bottom seal just contacts the floor without crushing.
• Store the setting: Press the program/confirm button to save the new down limit. The opener may automatically run a test cycle.
• Inspect drive system: Check the chain or belt tension and the drive sprocket on the motor shaft. Tighten any loose set screws and adjust tension so there is minimal sag but no binding.
• Test multiple cycles: Run the door through several open/close cycles to confirm it stops correctly at the floor and the error no longer appears.
• If limits drift again: The limit encoder or internal sensor on the Marantec head may be failing and the control head may need replacement.