A door that starts down and then reverses, or will not move at all, is nearly always being stopped on purpose by a safety feature. Work through these checks in order. The first three solve most cases.
1. Something is blocking the safety sensors
Two sensors sit a few inches off the floor on either side of the door. If anything breaks the beam between them, the door will not close. Look for a broom handle, a bin, leaves, or a spider web across a lens.
2. The sensors are out of alignment
Each sensor has a small indicator light. Both should glow steadily. If one is flickering or off, it has been knocked out of line. Loosen its wing nut, aim it at the opposite sensor until the light holds steady, and retighten.
3. Sunlight is hitting a sensor
If the problem appears only in the early morning or late afternoon, low sun may be flooding the receiving sensor. Shade it with your hand as a test. A small sun shield, or swapping the two sensors to opposite sides, is the usual fix.
4. The close limit or force setting has drifted
If the door reaches the floor and then goes back up, the opener thinks it has hit an obstacle. The travel limit or close force needs adjusting. Your opener’s manual shows where the adjustments are; make small changes and retest the safety reversal afterward.
5. The track is obstructed or bent
Look along both tracks for debris, a loose bracket or a dent. Do not force the door past a tight spot.
6. A spring or cable has failed
If the door closes fast, looks crooked, or you can see a loose cable, stop. This is not a sensor problem. See spring repair and cable repair.
7. The remote is locked out or the opener has a fault
If the wall button works and remotes do not, the wall console’s lock feature may be on. If nothing works and the sensors look fine, the opener’s wiring or circuit board needs testing.
A temporary way to close the door
On most openers, pressing and holding the wall button overrides the sensors and closes the door. Use this only while watching the door, and only to secure the house until the sensors are repaired. Never tape or wire sensors together to bypass them.
