Door will not fully open or stops partway; opener beeps and shows F4.

Safety first: Do not attempt to adjust or replace torsion springs yourself; they are under high tension and can cause serious injury.

• 1. Disconnect opener and test door manually: Pull the emergency release and lift the door fully by hand. If it is heavy or will not open fully, the springs may be weak or broken and require professional replacement.
• 2. Inspect upper tracks and hardware: Check the horizontal tracks for bends, loose brackets, or obstructions. Ensure the top roller brackets and hinges are secure and not binding.
• 3. Verify travel limits: Reconnect the opener. Locate the Linear open (up) limit adjustment on the head unit. Adjust slightly in the direction that allows more open travel, following the manual.
• 4. Adjust up force (if door is balanced): If the door moves freely by hand, increase the up force slightly on the opener. Do not over-adjust; the opener should not strain or jerk.
• 5. Run a full cycle: Operate the door from closed to fully open and back. Confirm it reaches the full open position without stalling and that F4 clears.
• 6. If problem persists: If the door is mechanically sound and adjustments do not help, the Linear opener’s force sensing or limit circuitry may be failing; consider replacing the operator head.