Garage Door Will Not Close: Photo Eyes, Obstructions and When to Stop

No. Safety sensors and reversal features should be restored to proper operation, not bypassed.

Not necessarily. Diagnosis may identify sensor position, wiring, control or a separate mechanical problem.

The most common cause by far is the photo-eye safety sensors near the floor no longer seeing each other — misaligned, dirty, blocked, or with a damaged wire. The opener treats that as an obstruction and reverses, which is the system working correctly. Less often it is a travel or force setting, or a real obstruction in the track.

From a safe standing position, look at the two small sensors near the floor on each side of the opening. Most have indicator lights; a steady light on both usually means aligned, a flashing or off light means not. Gently wipe the lenses and check nothing is leaning in the beam. Do not attempt to rewire them.

No. The photo eyes are the entrapment-protection system federal rules have required since 1993, and defeating them removes the protection that stops a door closing on a child, pet or obstruction. If a door will not close because of the sensors, the sensors are fixed or replaced — never bypassed.

A knock from a bin, a bike or a vehicle; a bracket working loose over time; heavy vibration; or a wire pulled where it runs along the track. In a garage where things are stored near the opening, a bumped sensor is one of the most common of all opener complaints and often the cheapest to resolve.

Then the cause is more likely a travel or force setting that needs adjusting to the door, a genuine obstruction or binding in the track, or a mechanical resistance the opener is reading as an object. Those are diagnosed on the door rather than adjusted blindly, because raising the force to overpower resistance removes a safety margin.

Yes — cold stiffens lubricant and a partly frozen threshold adds resistance, and the opener may read that as an obstruction and reverse. It can also cause condensation on the sensor lenses. If it only happens in the cold, the door's condition is usually the real subject rather than the opener.

Many openers use a blinking light as a deliberate signal, and a sensor fault is the most common thing it reports. The blink pattern differs by brand and the manufacturer's manual decodes it. So a blinking light plus a door that will not close is very often the same single problem: the photo eyes.

If the door reverses reliably, the safety system is doing its job and the main effect is inconvenience. What is not safe is disabling the reversal to make it close, or repeatedly forcing it. If the door is closing unpredictably or slamming, stop using it and request service.

Replacing sensors involves low-voltage wiring and correct alignment, and doing it wrong can leave a door that appears to close but no longer protects against an obstruction. Because it is a safety component, it is worth having it done and tested properly with a real obstruction test rather than assumed working.

By testing the reversal with a real obstruction — an object laid flat in the door's path should make it reverse on contact — and by confirming the photo-eye beam reverses the door when broken during a close. A repair that ends without those two tests has not established that the door is safe.