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Garage Door Sensor Repair in the North Shore
Doors that reverse, won't close, or only close while you hold the button — diagnosed and fixed, usually the same day.
Every garage door opener has two small safety sensors, one on each side of the door about six inches off the floor. One sends an invisible beam and the other watches for it. If anything breaks that beam while the door is closing, the opener sends the door back up.
That's exactly what you want when a child or a bike is in the way. It's a lot less welcome when the sensors are simply out of line and the door refuses to close on its way out of the driveway. The good news: most sensor problems are quick, inexpensive fixes.
Symptoms and causes
Signs your sensors are the problem
Door goes down, then right back up
The classic sensor fault. The opener isn't seeing a clear beam, so it reverses as a safety precaution.
Only closes while you hold the button
That's the opener's built-in override for a sensor problem. It will close while someone is watching, and not otherwise.
Opener light blinks
Many openers flash their light or click several times to report a sensor error. The pattern depends on the brand.
Sensor light is off or flashing
Usually one sensor has been bumped out of line, or a wire has been damaged, chewed or pinched along the wall.
Fails at the same time every day
Low morning or afternoon sun shining straight into one sensor can blind it. Common on east- and west-facing garages.
Works some days, not others
Loose brackets, corroded connections or moisture inside an older sensor. Cold snaps make it worse.
Before you call
Three things worth checking yourself
Wipe the lenses. Dust, cobwebs and road spray are enough to block the beam. A soft dry cloth is all it takes.
Look for something in the way. A recycling bin, a rake or a pile of leaves sitting in the path of the beam will stop the door every time.
Check that both sensors point at each other. If one has been knocked, its light will usually be off or blinking. Gently nudge it back until the light holds steady.
If none of that works, or the wiring looks damaged, give us a call. Please don't disconnect or tape over the sensors to get the door closing — they're there for a good reason.
What we do
Sensor alignment, wiring and replacement
We re-align and re-secure the brackets, repair or re-run damaged wiring, and replace sensors that have failed. We also run a full safety-reverse test before we leave, so you know the door will stop and reverse the way it's supposed to.
Sensors are part of the opener system, so if the opener itself is showing its age we'll look at that too. See our garage door opener repair page for more on repair-or-replace decisions.
Common questions
Sensor problems, answered
Why does my garage door reverse before it closes?
Nine times out of ten it's the safety sensors. The two small photo-eyes near the floor on either side of the door have to see each other. If one is knocked out of line, dirty, or its wire is damaged, the opener thinks something is in the way and sends the door back up.
How do I line up my garage door sensors?
Loosen the wing nut on the sensor that isn’t showing a steady light, then gently pivot it until its light holds steady and the other sensor stays lit. Tighten it back down and test the door. If neither light comes on at all, it’s usually a wiring or power problem, and that’s worth a call.
Why does my garage door only close if I hold the wall button down?
Holding the button is the opener's manual override for a sensor fault. It means the opener isn't getting a clear signal from the photo-eyes, so it will only close while you're standing there watching. It's a sign the sensors need alignment, cleaning or replacement.
What do the lights on the sensors mean?
Most openers have a light on each sensor. A steady light on both usually means they're aligned. A blinking or dark light on one side usually means it's out of line, blocked, or not getting power. The exact meaning varies by brand.
Can low sun stop my garage door from closing?
Yes. On west- or east-facing garages, low sun shining straight into one sensor can blind it for part of the day, so the door reverses at the same time every afternoon. Swapping which side each sensor sits on or shading the receiver usually fixes it.
Can I just disconnect or bypass the sensors?
Please don't. Federal safety rules have required them on every opener since 1993 because a closing door can seriously hurt a child or pet. A sensor fault is usually a quick, inexpensive repair.
Where we work
We do garage door sensor repair in…
Get it sorted
Door won't close?
Tell us what it's doing and we can often talk you through a quick check on the phone before we come out.