A garage door sensor is an essential feature that ensures a heavy garage door’s safe and functional operation. The sensor’s infrared eyes detect cars, pets, boxes, trash cans, people, or anything else that gets in the way of the moving garage door. Garage door sensors became mandatory in 1993, so you must ensure your garage door has one.

Garage door sensors sit about 6 inches from the ground on either side of the door. These two infrared sensors create an unbroken line across the bottom of the door when there’s nothing in the way. If there’s an obstruction, the sensor will stop the garage door from moving. The sensor light provides essential information about the garage door sensors, so understanding what the various light colors mean is important. Keep reading as our Chicago-area Overhead Garage Door team discusses everything you need to know.

What Does a Yellow Light on a Garage Door Sensor Mean?

Garage door openers traditionally function with red and green lights, but several brands use yellow (or amber) lights in certain instances instead.

Chamberlain, LiftMaster, or Craftsman Garage Door Openers

The transmitting photo eye on a garage door sensor has a yellow light that should remain lit. The yellow light indicates the garage door sensor is successfully sending an infrared beam across the bottom of the door to check for obstructions. If the yellow light isn’t illuminated, the garage door sensors aren’t sending a signal, and the garage door is a safety hazard.

When the yellow light is off, you should check for the following problems:

  • A broken wire from the motor head to the sensor light.
  • A faulty photo eye.
  • A bad logic board.

What Does a Green Light on a Garage Door Sensor Mean?

Green lights usually mean things are good. Several brands use green garage door opener lights in a very particular way.

Chamberlain, LiftMaster, or Craftsman Garage Door Openers

The receiving eye for a Chamberlain, Craftsman, or Liftmaster garage door sensor should always be illuminated green. If the yellow light is off, the green light will also be off because there’s nothing this sensor can receive if the transmitting eye isn’t working. If the yellow light is on, but the green isn’t, the photo lenses aren’t properly communicating. You can troubleshoot this problem by following the steps below:

  • Clean the eye lenses.
  • Loosen the thumbscrew and carefully move the eyes to adjust their position so they point directly at each other.
  • Check the wires from the motor head to the sensor light.
  • Check for a bad logic board.

Guardian and Marantec Garage Door Openers

Both Guardian and Marantec garage doors have a green transmitter light. When this is illuminated solidly, the infrared light communicates successfully across the bottom of the door.

What Does a Red Light on a Garage Door Sensor Mean?

Most people think of a red light as a hazardous warning sign, but many garage door openers use a red light as a sign of a functioning unit. A red light can mean several things on a garage door.

Genie and Guardian Garage Door Openers

The transmitting and receiving eyes for a Genie garage door opener are red. On the Guardian garage door, only the receiving light is red.

A solid red light for both Genie and Guardian doors means this part of the garage door sensor is working properly. If the light is flashing, there’s likely an obstruction blocking the light. If the light is off, you should follow the troubleshooting suggestions for the yellow transmitting light above to diagnose the issue.

Marantec Garage Door Openers

The receiver light for the Marantec garage door is red. It illuminates solidly when both lenses are in proper alignment. The red light won’t turn on if the sensors aren’t aligned.

What Does an Orange Light on a Garage Door Sensor Mean?

Garage door openers don’t typically have an orange light, although many have an amber LED light. Most brands describe this as yellow; the above section on yellow garage door opener lights applies.

Understanding Garage Door Openers

As you can see, the color of garage door opener lights isn’t universal across all units. The above guidelines apply to some popular garage door opener brands, but it isn’t an exhaustive listing, and new units may function differently from what we’ve reviewed.

Consult the owners manual for an accurate and detailed description of your unit’s garage door opener lights. Some systems use green lights to indicate proper function and red lights to alert you to errors. A flashing light nearly always means there’s an issue. Some units flash in different patterns to give more detailed information about what’s wrong.

Garage Door Sensor Maintenance

A garage door’s sensor lights require regular care and maintenance to stay in prime condition. Regularly cleaning the lenses ensures they can shine clearly across the expanse of the door. Garages can easily accumulate dust, dirt, and spiderwebs. Take a microfiber cloth to clear away anything obstructing the light. Gently wipe the lens to keep it clean.

Visually inspect the wires connecting the garage door sensors to the receiver box. Look for signs of fraying, damage, or wear. If you can tell the wires are coming apart, replace them as soon as possible to avoid any interruption in the garage door function.

Garage Door Opener Repair in Greater Chicago

If your garage door sensors aren’t working, the door won’t function. It’s a safety measure to ensure nothing gets crushed under the door’s weight. You may be able to remedy the issue with one of the simple measures we’ve discussed. You may need a professional repair if your garage door doesn’t respond to these quick fixes. Contact our team at Overhead Garage Door for a thorough assessment and expert garage door repair.