To replace garage door safety sensors, unplug the opener, wire the solid white wire to the white terminal and the white and black wire to the black or gray terminal, mount each eye no higher than 6 inches above the floor, then align them until both lights glow steadily. Test the reversing system afterwards. Never bypass the sensors.
First, confirm the sensors are the problem
Each sensor has a small light. On Chamberlain and LiftMaster sensors, the amber light marks the sending eye and the green light marks the receiving eye. If one or both lights are dark or flicker, the eyes may be misaligned, dirty or wired badly.
Chamberlain's diagnostic codes for its Wi-Fi openers also help. Code 1-1 means the sensors are not detected or a wire is cut, 1-2 means the wire is shorted or reversed, and 1-4 means the sensors are misaligned or were briefly blocked. Try cleaning and realigning first, as in why the sensors blink. Replace only when the eyes or the wire are damaged.
What you need
- A replacement sensor kit that matches your opener's model
- Wire strippers and a screwdriver
- Wire of two colors, if the old wire is damaged
- A short stepladder
- Your opener's manual for terminal names
Chamberlain says power must be disconnected before the sensors are installed.
Steps to replace the sensors
Unplug the opener
Disconnect power at the outlet before you touch any wire.
Remove the old eyes
Loosen the wing nuts and brackets, then disconnect each pair of wires. Note which wire goes where.
Mount the new brackets
Mount one on each side of the door, no higher than 6 inches above the floor, with the wing nuts finger-tight.
Wire each eye
On each sensor, connect one wire color to the solid white wire and the other color to the white and black striped wire. Use the same color pairing at both eyes.
Wire the opener
Connect the solid white wires to the white terminal and the white and black wires to the black or gray terminal. Terminal names differ a little by model, so check your manual.
Align the eyes
Restore power and aim the eyes at each other until both lights glow steadily and do not flicker, then tighten the wing nuts.
Test the door
Close the door with the wall control and block the beam with a broom handle. It must stop and reverse. Then run the 2x4 reversal test.
Chamberlain's diagnostic code 1-2 tells you to check the wire at every staple and connection point. Leave a little slack and do not pinch the wire in a staple.
Mistakes to avoid
- Never disconnect or tape over the sensors so the door will close. A door that ignores its sensors is a hazard.
- Do not mount the eyes higher than 6 inches above the floor.
- Do not swap the white and the white and black wires, because a reversed wire sets off the wiring fault code.
- Do not hang anything on the door or tracks that crosses the beam while the door closes.
- Do not skip the test. Chamberlain says to test the reversal monthly and after any adjustment.
Testing the reversal
Chamberlain says the door must reverse on contact with a 1-1/2 inch object, which a 2x4 laid flat matches. See garage door safety tests for the full routine. If the door does not reverse, stop using the opener's automatic close and call a technician.
When to call
If the opener still shows a sensor fault after new eyes, the problem may be in the wire inside the wall or in the logic board. A tune-up, roller set or sensor job is typically $150 to $350 with us, and the final price is confirmed after we see the door. See opener repair and garage door repair. We serve homes in cities such as Glendale, Clearlake and San Juan Capistrano. Call (213) 340-4232 or send the estimate form.
Questions people ask
How much does it cost to replace garage door sensors?
A sensor job, roller set or tune-up is typically $150 to $350 with us. The final price is confirmed after we see the door.
Why won't my new garage door sensors line up?
Check that the eyes face each other at the same height, that nothing blocks the beam and that the wire is wired to the right terminals. Both lights should glow steadily.
Can I wire garage door sensors without a diagram?
Use the opener's manual. In general solid white wires go to the white terminal and white and black wires to the black or gray terminal, but names vary by model.
Is it safe to bypass the garage door sensors?
No. The sensors are a safety system that makes the door reverse. If they fail, have them fixed instead of disabling them.
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