Symptoms
- Door won't close, or closes then immediately reverses
- One or both sensor indicator lights are off or blinking
- Sensors were bumped, or something recently changed near the door
Likely causes
- CommonSensor bracket bumped out of alignmentA bike, ladder, or vehicle brushing against a sensor can knock it out of alignment.
- CommonDirt, cobwebs, or moisture on the sensor lensEven a small obstruction on the lens can block the beam.
- PossibleDirect sunlight interfering with the sensorStrong low-angle sunlight can sometimes overwhelm a sensor's receiver.
- PossibleLoose sensor wiringA partially disconnected wire can cause intermittent alignment-like symptoms.
What to do
- Locate both sensors, mounted a few inches off the floor on each side of the door track.
- Wipe both sensor lenses clean with a soft, dry cloth.
- Check each sensor's indicator light; typically one should be solid and steady, not off or blinking, when aligned.
- Loosen the wing nut or screw holding the sensor bracket and gently adjust the angle until the light becomes steady, then retighten.
- If sunlight seems to be the issue, consider shading the sensor slightly or adjusting the angle away from direct light.
- Test the door's full close cycle after alignment to confirm the issue is resolved.
Tools and parts
- Soft cloth
- Screwdriver
Garage door safety sensor pairSearch: “garage door opener safety sensor replacement”
When to call a pro
Call a garage door technician if realignment doesn't fix a blinking or unresponsive sensor, since the sensor unit or wiring may need replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.