Garage Door Safety Sensors
Safety sensors are the two small photo eyes mounted a few inches above the floor on each side of the opening, sending an invisible beam between them. Federal law has required them on every opener sold since 1993. If the beam is broken, misaligned or dirty the door will not close, and it is by a wide margin the most common reason a garage door refuses to shut. Repair runs $95 to $300, and several of the causes cost nothing to fix yourself.
Covered by Garage Door Opener Repair · from $95
One sensor sends, the other receives. If the receiver does not see the beam, the opener refuses to close the door, and if the beam breaks while the door is coming down it reverses immediately. That is the behaviour keeping a child or a pet from being caught underneath.
Because the requirement is federal and dates from 1993, every opener you are likely to have has them. It is also why bypassing them is a genuinely bad idea rather than a technicality: the reverse is the last line of protection on a door that weighs more than the person standing under it.
The good news is how often this is free to fix. Most sensor faults are a lens with a cobweb across it, a bracket knocked by a bike, or sunlight hitting the receiver at a low angle, and all three are five minute problems.
How to tell this part has failed
- The door starts down then immediately goes back up
- The door will not close from the remote but will from the wall button held down
- One sensor light is off, or flickering, when the other is steady
- The opener light flashes a set number of times when you try to close
- The door closes fine in the morning and refuses in the late afternoon
- The door only closes if you hold the wall button the whole way
Why it fails in Florida
Misalignment is the biggest cause and it takes very little. A bike, a bin, a vacuum hose or a foot catching a bracket moves it a few degrees and the beam misses.
Florida grime on the lens. Dust, cobwebs, lawn clippings and salt film build up on the plastic, and a spider web across the lens is enough to break the beam.
Low sun. A sensor facing west can be blinded by direct afternoon sunlight, which is exactly why a door that behaves all morning refuses at five o clock.
Wiring. Staples through the cable, rodent damage, and corroded terminals in a humid garage all produce an intermittent fault that comes and goes.
Can you do this yourself
Yes, this one you can do
Try this before you call anybody. Wipe both lenses with a soft dry cloth. Look at the indicator light on each: they should both be on and steady, and one blinking usually means alignment. Loosen the wing nut, move the bracket slightly until both are steady, and tighten. Check nothing is parked in the beam. If the fault only appears at a particular time of day, a small sun shield on the receiver often ends it. If both lights are dead, that is wiring and worth a technician.
Starting prices for a standard single door. Your final price depends on the door, the model, the wind rating a replacement needs and what we find. You get a written quote before any work starts.
Have a technician bring this part
Leave your details and we call you back to confirm the part, the price and a time. The technician arrives with it on the truck.
Garage Door Safety Sensors
Not sold separately. Price shown is fitted, by a technician who brings the part.
(561) 897-9930Frequently Asked Questions
Can I just disable the sensors?
No, and we will not do it either. They are federally required on every opener sold since 1993, and they are the reason a door reverses instead of closing on a child, a pet or a foot. A door that will not close is an inconvenience for a day. The thing the sensors prevent is not recoverable. If yours are faulty we fix or replace them.
Why does the door close in the morning but not the afternoon?
Almost always low sunlight hitting the receiving sensor. Late afternoon sun coming straight into the lens overwhelms it and it stops seeing the beam from its partner. A small shield or hood over the receiver, or repositioning it slightly, usually solves it permanently. It is a genuinely common Florida fault on west facing garages.
Both sensor lights are off completely. What does that mean?
No power reaching them, which is wiring rather than alignment. Common causes are a staple driven through the cable during some other work, rodent damage, a corroded terminal at the opener head in a humid garage, or a wire pulled loose. That is worth a technician, because it means working at the opener terminals.
