Door stops and reverses immediately when trying to close; opener beeps and shows F3.

Safety first: A door that binds or has spring issues can be dangerous. Do not attempt spring adjustment unless you are trained; contact a professional for spring or counterbalance work.

• 1. Check for obvious obstructions: Inspect the full travel path of the door. Remove any debris, ice, or objects in the tracks or on the floor at the door threshold.
• 2. Inspect tracks and rollers: Look for bent vertical or horizontal tracks, loose track brackets, or rollers that are off-track or seized. Straighten minor bends and tighten loose brackets. Replace damaged rollers.
• 3. Test door balance (with opener disconnected): Pull the emergency release cord to disconnect the Linear opener from the door. Manually lift the door halfway and release. It should stay in place. If it slams down or shoots up, the springs are out of balance and require a professional technician.
• 4. Lubricate moving parts: Apply a garage-door-safe lubricant to rollers (metal wheels only), hinges, and bearings. Do not lubricate plastic rollers or the tracks themselves.
• 5. Adjust down force (if door is mechanically sound): On the Linear head unit, locate the force adjustment controls. Increase the down force slightly per the owner’s manual, then test. Do not exceed recommended settings; the door must reverse when hitting a 2x4 laid flat on the floor.
• 6. Reconnect opener and test: Re-engage the trolley, then run a full open/close cycle. If F3 persists despite a smooth, balanced door, the force sensor circuitry in the opener may be faulty and the operator head may need service or replacement.