Signs of a sensor problem
- The door will not close with the remote, but closes if you hold the wall button
- The door reverses right after it starts down
- The opener lights blink when you try to close the door
- One sensor light is off, dim or flickering
- The problem comes and goes, often at certain times of day
Real examples from our jobs
How the sensors work
Two small sensors sit a few inches above the floor on either side of the door. One sends an invisible infrared beam and the other receives it. If anything interrupts the beam while the door is closing, the opener reverses. Federal safety rules have required this kind of entrapment protection on residential openers since 1993.
Common causes
- Misalignment. A sensor bumped by a trash bin, bike or broom no longer points at its partner.
- Dirty lenses. Dust, cobwebs and grass clippings block the beam.
- Sunlight. Low sun shining directly into the receiving sensor can wash out the beam. This is common on east- and west facing garages and explains problems that appear at the same time each day.
- Damaged wiring. Staples through the wire, corrosion at the terminals, or wire chewed by rodents.
- A failed sensor. Electronics do wear out, particularly near a damp floor.
What you can check first
Wipe both lenses with a soft cloth, make sure nothing is in the doorway, and look at the indicator lights. Both should be steady. If one is blinking, gently adjust that sensor until the light holds solid. If the lights are steady and the door still will not close, or the lights will not come on at all, the fault is in the wiring, the sensor or the opener’s board, and it is time to call.
Never bypass or tape the sensors together to make the door close. They are there to protect children, pets and vehicles.
What to expect from a Tier One visit
Call or send a request
Tell us what the door is doing. We’ll give you the earliest time we can be there.
We diagnose the problem
The technician inspects the whole door system, not only the part that failed.
You approve the price
You get a clear explanation and the price before any work begins.
We repair and test
The door is repaired, balanced and safety tested before we leave.
Garage Door Safety Sensor Repair FAQs
Why does my door close only when I hold the wall button down?
Holding the wall button overrides the sensors, which is built in so you can close the door in a pinch. It confirms the opener is fine and the sensors are what is stopping it.
Can sensors be replaced without replacing the opener?
Yes. Sensors are a separate part. They do need to be compatible with your opener’s brand and generation.
How high should safety sensors be mounted?
No higher than six inches above the garage floor, so the beam can detect a small child or pet lying in the doorway.
