Garage Door Won’t Close? Photo-Eye Sensor Fixes
If your garage door won’t close — it starts down then reverses, or the opener light blinks — the photo-eye safety sensors near the floor are almost always the cause. Clean both lenses, make sure nothing blocks the beam, and realign them until both indicator lights are solid. If the lights still won’t hold steady, the sensor or wiring has failed and needs a technician.
- A blinking opener light usually means a sensor fault, not a motor problem.
- The sensors sit about 6 inches off the floor on each side of the door.
- Clean lenses and clear the beam path first — cobwebs and dust are common culprits.
- Both indicator lights must be solid; a flickering light means misalignment.
- Frayed wiring or a dead sensor is a technician fix, not DIY.
Why the door reverses
Every modern opener has two photo-eye sensors near the floor that shoot an invisible beam across the opening. If anything breaks that beam — or the sensors lose alignment — the opener refuses to close (or reverses) as a safety measure, and the wall button or opener light blinks to tell you.
Clean and realign
Start simple: wipe both lenses with a soft cloth and clear away cobwebs, leaves, or anything sitting in the beam path. Then check alignment — gently adjust each sensor until both indicator lights glow solid. A flickering light means they’re still not pointed at each other.
When it’s not the sensors
If the lights stay dark or keep flickering after cleaning and realigning, the problem is deeper — a knocked-loose bracket, frayed wiring, or a failed sensor. That’s a quick technician fix, and it’s worth doing right since the sensors are the door’s main safety system.
We diagnose and repair safety sensors, wiring, and openers on every major brand — from $159 across London + 50 km, same-day where possible.
Frequently asked questions
Why does my garage door open but not close?
Almost always the photo-eye safety sensors. If the beam is blocked or the sensors are misaligned, the opener reverses or refuses to close and the light blinks. Clean and realign them so both indicator lights are solid.
Where are the garage door safety sensors?
They sit about six inches off the floor on each side of the door opening, facing each other. One is usually a sending unit and the other receiving.
Can I disable the garage door sensors?
No — they’re a required safety feature that stops the door from closing on a person, pet, or car. If they’re faulty, repair or replace them rather than bypassing them.
Related guides
Essential Garage Door Opener Parts You Should Know
Motor, drive, trolley, logic board, safety sensors, remotes — what each opener part actually does, and the ones that fail first.
Common Garage Door Repair Issues and Solutions
Door won’t close, grinding noise, off its track, slow to respond — the most common garage door issues and what actually fixes each.