My Garage Door Opener Light is Flashing and My Door Won’t Close

My Garage Door Opener Light Is Flashing & It Won’t Close!

This video demonstrates what to do if your garage door won’t close and the lights on the Chamberlain garage door opener are flashing.

Chamberlain garage door openers are equipped with safety reversing sensors. The safe reversing sensors must be installed and aligned correctly before the garage door opener will move in the down direction. When the light beam is obstructed, or the safety reversing sensors are misaligned. While the door closes, the door will reverse, and the garage door opener lights will flash ten times. The safety reversing sensors’ LEDs glow steadily when aligned and wired correctly. If the safety reversing sensors are blocked or misaligned, the garage door opener will not close the door.

First, check for an obstruction that may be blocking the sensors. If there is an obstruction, remove it. Next, if the green led on the receiving sensor is flickering on or off, you’ll need to try to align it. To align the sensor, loosen the wing nut and adjust the position of the sensor until the green led glows steadily, then tighten the wing nut. You can now close the door with your remote control or door control.

Anytime you make adjustments, the safety reversal system must be tested. To test the safety reversal system, open the garage door with the door fully open, and place a one-and-one-half-inch board or a two x four laid flat on the floor centered under the garage door. Press the remote control or wall-mounted door control to close the door. The door should stop and reverse upon contact with the two-by-four. The Door returns to the fully open position. The opener beeps, and lights flash slowly five times. If the door reverses, remove the board, and the test is complete. If the door stops and does not reverse, check that your garage door opener is installed correctly.

When you see your garage door opener lights flashing and the garage door will not close, it could be the safety reversing sensors or the LOCK button.;

Note: You can close the garage door by pressing and holding the door control push bar until down travel is completed.
Note: Any garage door opener or replacement logic board manufactured after February 3, 2022, will no longer have this feature.

How to Align the Safety Reversing Sensors

The safety reversing sensors may have become misaligned or obstructed. Follow the steps below to realign the safety reversing sensors.  

  • Locate each safety reversing sensor.
  • The sensors are located on each side of the garage door no higher than 6 inches above the garage floor, usually fastened to the door tracks.
  • Loosen the wing nut on the front of the sensor, and align the sensor so the lenses point at each other. When the sensor LED glows steadily, tighten the wing nut.
  • Once both reversing sensor LEDs glow steadily, test by using your remote or door control to close the garage door.

Note: If the above steps do not work, loosen both sensors, realign them, and test again. 
There may be a problem with the sensor(s), or wiring or sunlight can also cause interference causing the opener to act as if the sensors are obstructed. The sunlight shining into the receiving sensor (green LED) can block the infrared light from the sending eye (amber LED). Check out the Sunlight Interference with safety sensors article for steps to resolve this issue. 

How to Unlock the LOCK Button

The lock function may have been turned on if your door control has a LOCK button. When the LOCK button is ON, the garage door opener will work from the door control, but the remote controls are locked out.

  1. Press the LOCK button to turn this feature off. The light will flash two times.
  2. Press the remote control. If the door closes, your issue is solved.

Diagnostic Chart for Garage Door Opener

The garage door opener has a Self Diagnostic feature to help you determine the issue. Depending on the model of the garage door opener, the LED next to the learn button may flash several times, or the UP and DOWN arrows flash several times to indicate the issue. See What Does the Flashing LED Next to the Learn Button Mean for more help.

If the opener has the up and down arrows, you can use the table below to diagnose and resolve the issue.

 LED   UP and  Down Arrow Symptom Article
 1 1 Up 1 Down Wires are cut or not connectedHow To Troubleshoot The Safety Reversing Sensors When Both LEDs Are Not Lit
 2 1 Up 2 Down Wires are reversed, or there is a short in the wiringHow To Troubleshoot The Safety Reversing Sensors When Both LEDs Are Not Lit
 4 1 Up 4 Down Safety Sensors are misaligned or were momentarily obstructedHow to Align Safety Reversing Sensors

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