You press the button, the door starts down, then stops and heads back up. Or it doesn't move at all and the lights on the opener blink ten times. Nine times out of ten, that's the safety sensors, not a broken opener. Here's how they work, what usually goes wrong, and what you can safely check yourself.
Two small eyes sit on either side of the door opening, about four to six inches off the floor. One sends an invisible infrared beam to the other. If anything breaks that beam while the door is closing, the opener reverses. It's a federally required safety feature, and it's why a door with a dirty or misaligned sensor refuses to close.
Look at the small indicator light on each sensor. Both should glow steady. If one is dark or blinking, that's the side with the problem. Wipe both lenses with a soft dry cloth, clear anything near the beam, and gently nudge the bracket until the light goes steady. Check that the wire is intact from each sensor up to the opener head. If the lights come on steady, test the door by closing it with a cardboard box in the path — it should reverse on contact.
If you need the door closed right now, you can hold the wall button down until the door reaches the floor. The opener ignores the sensors in that mode. Treat it as a short-term fix only, since the safety reversal is disabled while you do it.
Call us if the sensor lights stay dark after cleaning, the wire is damaged, or the door still reverses with both lights steady. That points to a failed sensor, a wiring fault, or a closing-force or travel-limit setting on the opener. Don't touch the springs, cables, or bottom brackets while troubleshooting — those are under high tension and are never a DIY job. A sensor replacement is typically a quick visit, and we check the opener's reversal and limit settings while we're there.
Atlas Garage Door Service serves all of Utah County, Salt Lake County, and Juab County. Same-day appointments available — call or text now.
📞 Call 385-200-1517