If your garage door opens fine but refuses to close — or starts closing then immediately reverses — the problem is almost certainly the photo-eye sensors. These are the two small devices mounted near the bottom of your garage door tracks, about 6 inches off the floor. They shoot an invisible infrared beam between them, and if anything breaks that beam, the door will not close.
This is the single most common call we get. And about 80% of the time, the homeowner could have fixed it themselves in under 5 minutes.
How Sensors Work
One sensor is the transmitter (sends the beam), the other is the receiver (detects the beam). When the beam is connected, both LEDs show solid green. When something blocks or disrupts the beam, the receiver LED blinks and the opener refuses to close the door.
The system is designed to prevent the door from closing on a person, pet, or object in the doorway. It has been required on all garage door openers since 1993 (UL 325 federal safety standard).
Fix #1: Clean the Lenses (2 minutes)
This fixes it 60% of the time. The sensor lenses are tiny — about the size of a pencil eraser. They accumulate dust, cobwebs, and Central Oregon's volcanic grit quickly. One dirty lens is enough to break the beam.
Wipe both sensor lenses with a soft, dry cloth. Do not use glass cleaner or water — just a dry wipe. Check if both LEDs turn solid green. If they do, try closing the door.
Fix #2: Check for Obstructions (1 minute)
Look at the space between the two sensors. Is anything in the beam path? A broom leaning against the wall, a shoe, a bicycle wheel, a trash can lid? Even a spider web stretched across the opening can disrupt the beam on some models.
Also check: is the sensor itself tilted or bumped? Kids on bikes, lawnmowers, and pets knock sensors out of alignment regularly.
Fix #3: Realign the Sensors (3 minutes)
If cleaning did not fix it, one sensor is probably pointing slightly off-angle. The beam needs to connect perfectly between the transmitter and receiver.
- Look at both sensors. One should have a solid green LED (transmitter). The other should be blinking (receiver — it is not getting the beam).
- Loosen the wing nut on the blinking sensor's mounting bracket — just enough that you can move the sensor.
- Slowly adjust the angle of the sensor. Tilt it slightly up, down, left, right. Watch the LED.
- When the LED turns solid green, stop. Tighten the wing nut to lock it in place.
- Test by closing the door.
Fix #4: Check the Wires (2 minutes)
Each sensor has a wire running back to the opener motor unit. These wires can come loose from vibration, get chewed by mice (common in Central Oregon garages), or corrode at the connection points.
Check the wire connections at the back of each sensor — they should be tight with no exposed bare wire touching the bracket. Check the connections at the opener motor unit too. Push each wire firmly into its terminal.
Fix #5: Sunlight Interference
Direct sunlight hitting the receiver sensor can overwhelm the infrared beam. This usually happens in late afternoon when the sun is low. The door works fine all morning and refuses to close at 4 PM.
Solution: shield the affected sensor from direct sun with a small cardboard tube or buy sensor sun shields (about $5 at any hardware store). We see this frequently on west-facing garages in Bend.
When to Call a Professional
If you have tried all five fixes and the sensor still will not cooperate:
- The sensor itself may be dead — internal components can fail after 8-10 years
- The wiring may have a break somewhere inside the wall or ceiling
- The opener's logic board may have a sensor circuit failure
Call us at 541-203-7676. Sensor diagnosis and replacement is a quick job — usually under 30 minutes. Same-day service Mon-Fri.
Serving Bend, Redmond, Sisters & all of Central Oregon.