What the Sensors Do
The two small sensors near the floor on each side of the door shine an invisible beam across the opening. If anything breaks the beam while the door is closing, the opener stops and reverses. Openers made for U.S. homes since 1993 have had to include a second safety system on top of the auto-reverse, and on most homes it's these sensors. They're what keeps the door from closing on a person, a pet or a car.
Try These First
- Look at the little lights. Each sensor has one. On most openers both stay lit steadily when they're lined up. If one is off or blinking, the pair is out of line or something's in the way.
- Clear the path. A broom, a trash can or a leaf against the sensor is enough to block it.
- Wipe the lenses with a soft, dry cloth. Dust, cobwebs, frost and road-salt spray all block the beam.
- Line them back up. Sensors get bumped. Loosen the wing nut, aim the two at each other until both lights are steady, and tighten it again.
- Check for direct sun. Low morning or evening sun shining straight into a sensor can confuse it.
When to Call
If the lights still won't go steady, the wires may be damaged, loose at the opener, or chewed, or one of the sensors may have failed. Zach checks the wiring and the sensors, replaces what's bad, and tests the door with something in its path before he leaves.
Don't bypass the sensors or zip-tie them together to make the door close. They're what keeps the door from coming down on someone. If the opener itself is acting up, see opener repair.