Novoferm garage door opener shows E11 and the courtesy light flashes in a repeating pattern.

Safety first: Ensure the door is in a safe position and cannot fall before working on control wiring.

Steps to try:

• Check external controls: Inspect any wall‑mounted stop buttons, key switches, or control stations connected to the Novoferm opener. Ensure stop buttons are released and not damaged.
• Inspect wiring: With power off, check the cable from the external controls to the opener. Look for crushed or cut sections, especially where the cable passes through walls or conduits.
• Test by removal: Disconnect the stop circuit wires from the control board terminals and fit a temporary bridge if the manual specifies a normally closed loop. Power up and see if E11 clears.

If the error clears with the external wiring removed, repair or replace the external stop device or cable. If E11 persists with a correct bridge in place, the stop input on the control board is likely defective.