Chamberlain Garage Door Monitor Flashing Red And Green [5 Easy Solutions]

Chamberlain garage door monitor flashing red and green due to a weak or dying transmitter battery. Also, if there is transmission interference or poor signal, it leads to the same issue. Misalignment of the sensors is mostly responsible for this.

If you notice the red and green lights constantly flashing on your garage door opener unit, don’t get in trouble. We are here to bring the complete solution to this problem. 

Chamberlain Garage Door Monitor Flashing Red And Green [5 Easy Solutions]

We have assigned here every possible step that will be highly effective to fix this issue. Besides this, we will assist you to figure out the major reasons for occurring such issues in your unit. So, let’s move to the main section.

1. Weak Transmitter Battery

There is a remote control on the garage door monitor, which operates as the transmitter. The transmitter controls the built-in receiver in the garage door opener.

The transmitter runs through a battery system. If the battery is dead, it fails to transmit the signal to the receiver.

 Thus, the LED green and red lights will start flashing simultaneously. To prevent this, the batteries require frequent replacement in order to make sure durability and fluent door operation.

Anyway, blinking lights is one of the major signs of a weak battery. Anyway, if it’s more than 6 months old, your transmitter needs a new battery.


First, remove the back slot of the transmitter. When the battery will inspect, take out the dead battery. Then, insert the new battery in the same position. Here, make sure the batteries are placed tightly and properly aligned with the positive and negative signals.

2. Poor Signal or Transmission Interference

The poor signal between the door and the receiver is another root cause for causing light issues on the garage door opener.

Sometimes, poor signals turn the device into unreliable operating or not working at all. There needs a perfect distance for the transmitter to the garage door. 

Mostly poor signals occur for electrical interference. If there are any hard obstacles between the two devices, the receiver fails to catch the specific radio frequency sent by the remote transmitter.

Also, by having electrical appliances which have the same frequency as the transmitter, interferences occur. Anyway, go through the below solutions procedures:


  • First of all, make sure there are not any hard obstacles between the receiver and the garage door.
  • Also, remove all the appliances nearby at the same frequency.
  • Ensure the receiver is mounted to a close position to the garage door.
  • If it is possible to remove or reposition the receiver device, you may relocate the antenna out of the interference-producing source.
  • But before that, it is essential to figure out the antenna wires. For this, remove the back cover of your opener operator.

3. Erase The Sensor’s Memory

In all garage door monitors, there has an internal memory that features to remember all programmed keyless entry pads and remote controls. Sometimes, erasing all the old memory will prove well in the case of a flashing light. 

It will erase all the previous garbage memory and set it to default settings. After erasing memory, it hopes that the red and green light blinking will stop. So, without getting late, let’s get started:


  • First of all, safely access your Chamberlain opener.
  • Now, locate the ‘Learn’ button of your opener. You will find the learn button on the rear or side of your opener.
  • Press the button and keep holding the button for approximately 6 seconds.
  • This time, the LED light will turn off. All the previous programs are now erased.
  • After erasing the memory of all programmed sensors, the receiver will enter the learning mode.

4. Sensor Misalignment

As you already know that there are configured safety sensors in your garage door monitor. It features in order to prevent accidents.

The primary function is to ensure that there are not any obstacles blocking the path of the door when it is in closing command. 

So, it is essential to ensure that all the connections and positions of the sensor are secured. Blinking lights mostly happen due to the misalignment of the sensor.

If there is a constantly blinking red and green light, it may signify to you that the sensors are not correctly aligned.


  • To resolve this problem, first, locate the two photo eyes which are attached to your garage door.
  • Now, take a soft microfiber cloth and clean the lens.
  • Then unscrew the nuts that are holding up the photo-eye. After that, adjust each of the sensors until they are perfectly aligned and in the correct position.
  • If the alignment is correct, the blinking will turn off, but the green light will remain on. It will glow steadily.  

5. Reconnect the Unit

If all the above steps will fail to stop the blinking of the LED light, it is time to reconnect the unit. Go through the below suggested steps to reconnect the receiver unit.

  • First of all, unplug the power cord of your garage door monitor.
  • Wait for 2-3 minutes.
  • Now plug back in the unit’s power cord.
  • Make sure the connection point is well working.
  • If you still see both lights after turning on the monitor, raise your door once. Then again, lower the door.
  • After this, if your unit fails to resume to the back position, it is sure that the unit got defective.
  • Contact a professional or technician.


Is there a reset button on a Chamberlain garage door opener?

One can reset the Chamberlain garage door opener by pressing the ‘Learn’ button. First, locate the button from above the antenna wire that hangs from the motorhead. Hold the button for six seconds.

Why does my Chamberlain garage door opener not work?

If your garage door opener fails to respond, either there have dead transmitter batteries or a weak signal. Also, worn-out wires and defective sensors are highly responsible for this. 

Wrapping Words:

If you own a garage door monitor device, there is nothing more annoying than happening such a type of malfunction on it. To think about this, we have decorated this guide. 

Hopefully, all-over guides have well proved to you. Still, if you have any queries regarding this article, let us know through comments. We will be glad to help you.

Note: You can also read how to fix the Samsung baby monitor out-of-range problem.

About Gonzalez

William Gonzalez is a passionate researcher & electronics expert who is dedicated to solve complex electronic issues. Plus, he has a passion for sharing his knowledge & expertise in this field with others. Well, he breaks down the complex technical concepts into simple terms & shares them with his readers so that they can easily troubleshoot the problems with their electronic products as well as save their pockets.

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