When a garage door starts down, stops, goes back up and the opener light flashes, the opener is telling you one thing: the photo-eye safety sensors did not see each other. Here is how to read the signal and what to do about it.
What the blinking light means
On LiftMaster and Chamberlain openers, ten blinks means the sensor beam is blocked or misaligned. Genie openers flash a red LED on the motor head and the sensors themselves. Either way, the opener will not close the door until the beam is restored. This is a safety feature, not a malfunction.
The two-minute check
- Look at both sensors, mounted about six inches off the floor on each side of the door. One should show a steady amber or red light (sending) and the other a steady green light (receiving).
- A flickering or dark green light means misalignment. Loosen the wing nut, nudge the sensor until the light is solid, tighten it.
- Wipe both lenses with a soft cloth. After a Phoenix dust storm this alone fixes most calls.
- Clear anything in the doorway: a hose, a trash can, a spider web, a kid’s bike.
Sun in the sensor
West-facing garages in Phoenix get low afternoon sun straight into the receiver lens, which overwhelms it. A piece of PVC pipe or a cardboard shade over the receiver, or swapping the sender and receiver sides, solves it.
When it is a wiring or sensor failure
If a sensor light stays off no matter how you aim it, check for a cut or stapled wire, a chewed section near the floor, or loose terminals at the opener. Sensors eventually die in the heat; a replacement pair must match the opener brand.
Temporary override
Hold the wall button down continuously until the door is fully closed. That bypasses the sensors for one cycle so you can secure the garage. Do not leave it that way.
Need it fixed today? See garage door sensor repair in Phoenix or call (602) 848-8510.
Frequently asked questions
Can I remove the safety sensors permanently?
No. They are required on every opener sold since 1993 and the opener will not close without them. Bypassing them permanently is unsafe and illegal.
Why do my sensors only fail in the evening?
Low western sun shining into the receiver. Shade the receiver or swap sensor sides.
