How do I fix garage door sensors that won't align?

The sensors are the small units mounted a few inches above the floor on each side of the door. One sends an infrared beam to the other. If that beam misses its target, the opener assumes something is blocking the door.

How to read the sensor lights

Every photo-eye has a small LED, and the colors tell you what's wrong:

• Both lights steady: the sensors are aligned and talking to each other.
• One light off or blinking: that sensor is misaligned, dirty, or losing power.
• Receiver light flickers when you wave a hand near it: wiring may be loose.

Knowing which sensor is dark saves time. The unit with the steady light is usually fine, so focus your adjustment on the one that's blinking or off. Brand colors vary, so check your opener's manual: on many models green is the sending eye and amber or red is the receiving eye, and a healthy pair shows one of each, both steady.

How to fix garage door sensor alignment

Work on one sensor at a time:

1. Clean both lenses with a soft, dry cloth. Dust, spider webs, and condensation block the beam more often than people expect.
2. Loosen the bracket by hand or with a screwdriver until the sensor can pivot.
3. Aim it straight at the opposite sensor. Tilt slowly until the LED turns steady.
4. Level the height. Both sensors must sit at the same height. Run a string or tape measure between them to confirm.
5. Tighten the bracket without nudging the sensor out of position.

Test by closing the door. If it travels all the way down and stays closed, the alignment is fixed. Hold the wall button to do a full close; if the door reverses, the sensors aren't seeing each other yet.

When alignment isn't the real problem

If the lights still won't go steady after aiming and cleaning, the cause is usually deeper:

• Pinched or chewed wiring. Staples driven too tight or rodent damage break the low-voltage circuit.
• Sun glare. Direct afternoon sun into the receiver can mimic a blocked beam. A small sun shield helps.
• A failed sensor. Sensors wear out, especially after water exposure or a hard bump.
• A bad opener logic board. Rare, but it presents the same way.

These need a meter to diagnose, not just a screwdriver.

A quick note on Colorado garages

Two local factors throw sensors off more than you'd expect. Snowmelt and grit get tracked in on tires and splash the low-mounted lenses, so they need wiping more often here. And the same long, low afternoon sun that's great for solar gain shines straight down many west-facing driveways into the receiver eye, faking an obstruction in late day. If your door only misbehaves at a certain time of day, glare is the likely culprit.

A quick test to confirm the fix

After any adjustment, close the door with the wall button while you watch the sensors, not the door. If both lights stay steady through the full travel and the door seals at the floor, the alignment held. If a light flickers as the door moves, a bracket is loose or the wiring is shifting. Snug everything back down and test again before you call it done.

When to call a pro

If you've cleaned, aimed, and leveled both sensors and the door still won't close, do not disable the safety system or tape the sensors to force it shut. That defeats the feature that protects kids and pets. A tech can test the sensors, the wiring, and the opener board in a single visit and replace whatever has failed.

A stuck or reversing door is one of our most common garage door repair calls in Lakewood, and a sensor fix is usually same-day. See the full range of issues we handle on our services page, all with flat-rate pricing.