The technician finds out whether the problem is alignment, an obstruction, wiring, a failed sensor or the opener itself, then confirms the door reverses as it should.
What safety sensors do
Safety sensors, often called photo eyes, sit on each side of the door opening near the floor. One sends an invisible beam to the other. If something crosses the beam while the door is closing, the opener stops and reverses the door.
They protect people, pets and objects in the doorway. The federal rule for openers made since 1993 requires entrapment protection, with an electric eye given as one example of an external device. Sensors must not be disabled or bypassed.
Signs your sensors need attention
- The door starts to close, then reverses or will not close at all.
- The opener light blinks, or the opener does not respond to the remote or wall control.
- A sensor light is dark, flickering or blinking.
- The sensors look knocked, bent or loose, or the lens is dirty.
- The wires are cut, frayed or pulled from the wall.
- The door closes only when the wall control is held down.
What the lights and blinks mean depends on the manufacturer. Check your model's manual. For more on the symptoms, read garage door safety sensors not working and why the opener light blinks.
What you can safely check
Before you book, there are a few safe checks. Do not use any of them to override the sensors.
- Look for something blocking the beam, such as a box, tool or stored item.
- Wipe each lens gently with a soft, dry cloth.
- Check that both sensors are still pointing at each other and are not loose.
- Look at the wire for visible damage, without touching bare wire.
- Read your opener manual for what its lights mean.
What we do on a sensor visit
The technician confirms the cause before replacing anything. Manufacturer support pages describe misalignment, obstruction, a faulty sensor and a short or broken wire as separate causes, and each is handled differently.
- We inspect the sensors, brackets, lenses and wiring along their full run.
- We check alignment and make sure nothing is blocking the beam.
- We test the wiring and the connection at the opener to find breaks or shorts.
- We realign, repair or replace the sensor or wire that failed.
- We confirm the mounting height is low, as manufacturers and DASMA specify.
- We test the door through full cycles and check that it reverses on contact with an obstruction.
Sensor height and placement
DASMA and CPSC both advise mounting photo eyes low. DASMA says they should not be installed higher than six inches above the garage floor, because a person or pet could pass under a higher beam without being detected. CPSC recommends a height of 4 to 6 inches. We check this on every visit, and we set them where your opener's instructions call for.
What affects the scope of the work
- Whether the sensors are misaligned, blocked, damaged or failed.
- Wiring problems, including broken, shorted or pulled wires.
- Whether the sensors are compatible with your opener or the opener board is at fault.
- Whether the door or tracks are also misaligned and pressing on a sensor.
- How far the wiring runs from the sensor to the opener.
Compare with garage door opener repair when the fault is inside the opener. See what affects garage door repair cost.
Safety: do not bypass the sensors
Never disable safety reverse
Do not disable, bridge or tape over a sensor to get a door to close. DASMA recommends that a trained technician adjust sensitivity and install the opener. Test your door's reverse each month, as CPSC advises, and stop using the opener if it fails the test. Our guides on auto-reverse and the safety reverse test explain how. Springs and cables are not sensor parts and stay technician work.
Where we provide this service
This service is available across New Jersey through our three regional teams.
Need this done?
A technician inspects the door first and explains what it needs.
Questions and answers
Why does my door reverse right before it closes?
A common cause is a blocked or misaligned sensor, but wiring, a failed sensor or opener settings can do the same. The technician confirms the cause. Check your manual for what your opener's signals mean.
What do the sensor lights mean?
It varies by manufacturer and model. One maker's support page describes steady lights as aligned, but other brands differ. Check your model's manual.
Can I bypass the sensors to close the door?
No. They are the entrapment protection, and they must not be disabled. If your door will not close, a technician should fix the cause.
Can sensors be replaced without replacing the opener?
Often yes, when the fault is a sensor or its wire. The technician confirms this by testing the sensors and the opener connection.
How high should the sensors be mounted?
DASMA says no higher than six inches above the floor, and CPSC says 4 to 6 inches. We check this during the visit.
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Our technicians repair, replace, install and maintain garage doors across New Jersey.