Since 1993, every garage door opener sold in the United States must include photo eye safety sensors. Those two small devices near the floor project an invisible infrared beam across the opening, and if anything breaks the beam while the door is closing, the door stops and reverses. When they act up, the door refuses to close, and most service calls about a door that will not close end at the sensors.
The five minute diagnosis
- Look at both sensor LEDs. Steady lights mean aligned, a blinking or dark LED marks the problem side.
- Clear the beam path: bins, brooms, cobwebs, and leaf piles are classic culprits.
- Wipe both lenses with a soft cloth, dust and spider webs scatter the beam.
- Check for sunlight glare, low sun hitting a lens confuses the receiver. A small shade tube fixes it.
- Gently nudge a knocked sensor back until its LED goes steady.
When it is the wiring
Sensor wires run stapled along the walls and ceiling to the opener head, and they are easily nicked by ladders, shovels, and mice. If the LEDs stay dark after cleaning and aligning, damaged wiring or a failed sensor is likely, both are quick professional repairs.
Never bypass the sensors
Holding the wall button forces the door down without sensor protection, and taping sensors together facing each other disables the system entirely. Both defeat the one feature protecting kids and pets from a closing door. If the sensors will not behave, fix them, do not bypass them.
