If your garage door starts closing but stops or reverses before reaching the floor, the cause is almost always one of four things: misaligned safety sensors, a down-limit setting that needs adjustment, an obstruction in the track, or worn rollers binding in the rail. Most homeowners can diagnose the cause in under 5 minutes.
Step 1: Check the safety sensors first (#1 cause, fixes 60%+ of cases).
Your garage door has two photo-eye sensors mounted at the bottom of each track, about 4-6 inches off the floor. Each sensor has a small LED. If either light is blinking — or one is off entirely while the other is on — they're misaligned and the opener thinks something is in the way. Gently nudge the brackets until both LEDs are solid. Wipe the lenses with a dry cloth (cobwebs and pollen are common offenders).
Step 2: Check for obstructions.
Walk along both tracks from top to bottom. Look for: pebbles, leaves, ice (in winter), a misplaced toy, a broken roller wedged in the track. Even a small object can stop the door. Run your hand along the bottom seal — sometimes a bunched-up weather-stripping prevents full close.
Step 3: Test the manual release.
Pull the red emergency release cord (the one hanging from the rail). This disconnects the door from the opener. Try to lift and lower the door manually. If the door moves freely and reaches the floor, the door system is fine and the issue is in the opener (likely the down-limit setting). If the door binds or won't reach the floor manually, the issue is in the door system (track, rollers, or hinges).
Step 4: Adjust the down-limit (if Step 3 showed the door is fine manually).
Most opener motors have two adjustment screws labeled UP and DOWN, usually with a flathead screwdriver slot. Each rotation = roughly 2 inches of travel. Turn the DOWN screw clockwise about ¼ turn at a time, run the door, and check if it reaches the floor. Stop adjusting when the door fully closes without slamming. If it slams, back off ¼ turn.
Step 5: If the door binds during manual operation (Step 3 showed binding).
This usually means a worn roller, a bent track, or a damaged hinge. These are not safe to ignore. The door will keep getting harder to operate and could come off the tracks entirely. Stop using the door and call us — we carry every common roller, hinge, and track repair part on every truck.
When to call instead of DIY: if you hear a loud bang and then the door stopped working, that's almost always a broken spring or cable — do not operate the door. If the door visibly tilts or hangs uneven, it has come off track. Both require professional service. Same-day repair available across MA.
