Garage Door Will Not Close: Photo Eyes and Obstructions
A door that will not close may be reacting to an obstruction, misaligned photo eyes, track resistance, travel settings or a mechanical door problem. Remove obvious objects only when the door is stable, check for blocked or dirty sensor lenses without bypassing them, and stop if the door is crooked, binding or has damaged cables or springs. Photo-eye sensors sit a few inches above the floor on each side of the track and must both see each other clearly. A stray leaf, cobweb, sunlight glare or a sensor that has been bumped out of alignment is enough to make the door reverse every time it tries to close.
Never tape over a sensor or hold the wall button to force a close. That defeats the entrapment-protection the sensors exist to provide. If clearing debris and checking alignment does not restore normal closing, the cause is more likely mechanical, track resistance, a travel-setting drift, or binding hardware, and deserves a proper inspection, not repeated workarounds.
| What | Detail |
|---|---|
| Category | Openers |
| Read time | 7 min |
| Related service | Opener repair |
| Questions answered | 10 FAQs below |
The safety system is doing an important job
Low sun can blind a photo-eye. Modern automatic openers use entrapment-protection features designed to reverse or stop a closing door. Bypassing photo eyes or holding controls to defeat normal protection is not a repair.
Safe things to notice
Without reaching into tracks or touching loaded parts, note whether both sensor indicators are on, whether sunlight or an object crosses the opening, and whether the door reverses at the same place each time.
- Object in the opening
- Dirty or moved sensor lens
- Track obstruction
- Door binds or becomes crooked
- Opener reports an error
When to request service
Request service when alignment will not hold, wiring is damaged, the door binds, reversal repeats with a clear opening or the system cannot pass the manufacturer's safety test.
A quick way to tell sunlight interference from a real fault
If the door closes normally at night or with direct sun blocked, but fails at a specific time of day when light hits the sensor lens, glare is a likely contributor and repositioning or shading the sensor may help. If failure is inconsistent regardless of light or time, suspect wiring, a damaged sensor or a mechanical cause instead.
Questions about garage door will not close: photo eyes and obstructions
How do I check the photo eyes myself?
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.
Does sensor trouble mean I need a new opener?
No. Not necessarily. Diagnosis may identify sensor position, wiring, control or a separate mechanical problem.
Can I temporarily disconnect a faulty sensor to get the door closed tonight?
No. Disabling entrapment protection removes a safety feature. Use the manual release for a stable, undamaged door instead and arrange sensor repair promptly.
Why does my door start to close then reverse?
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.
Can I bypass the sensors to force the door closed?
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.
Why would the sensors go out of alignment on their own?
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.
What if the sensors are clean and aligned and it still reverses?
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, not adjusted blindly, because raising the force to overpower resistance removes a safety margin.
Could cold weather make the door refuse to close?
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, not the opener.
Why does the opener light blink when this happens?
Many openers use a blinking light as a deliberate signal. 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.
How is a fixed door confirmed safe?
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.