Troubleshooting · 5 min read
Garage Door Won't Close: What to Check
Published
A door that won't close is usually a safety system doing its job — correctly or incorrectly. The pattern of the failure tells you where to look.
If it closes then immediately reopens
That's the reversing behavior triggered by the photo-eye sensors or the down-force setting. Check the two small sensors mounted near the floor on each side of the opening. Both should be aligned at each other, lenses clean, with a steady indicator light. A bumped bracket, a spider web, or sunlight hitting the receiver at a low angle will all do it.
Also clear the track path — a snow shovel leaning against the rail counts as an obstruction.
If it stops partway down
This is typically a travel-limit or force setting that needs adjusting, or something physically in the way — a worn roller catching where the track curves, debris in the track, or a hinge that's begun to bend.
If it won't respond at all to close
Check whether a sensor circuit is broken rather than misaligned. Many openers flash a code on the head unit or the wall console when the sensor circuit is open — a pinched or rodent-chewed sensor wire is a common culprit.
If it closes crooked or leaves a gap
That's mechanical, not electronic. Uneven cable tension, a drum that slipped, or a floor that isn't level will all leave a gap along one side. It's worth fixing rather than adjusting the limits to compensate, because a door that seals unevenly wears unevenly.
One thing not to do
Don't defeat the safety sensors to force the door shut. They're the mechanism that stops the door for a person, pet or bumper in its path.