Garage Door Won’t Close? Check Your Safety Sensors
There is nothing more frustrating than when your garage door won’t close. If you have to press and hold the inside wall button to close the garage door, your
Garage door opener
Automatic garage door openers manufactured after January 1st 1993 are required to have safety entrapment sensors.
The most common problem with
The second most common issue is the sending sensor can get weak over time and it won’t be strong enough to send the signal over to the receiving sensor. This is most common with double car garage doors due to the width of the opening. When this happens you will have constant intermittent issues with closing your garage door which can be very annoying. Also, it makes aligning the sensors much harder because the signal is weak. The lights on the sensors will be on but that doesn’t always mean you have a strong connection. Replacing the sensors is your best option.
Safety Sensors are Misaligned
The most common problem with garage door openers is safety sensor misalignment.
Even though you see lights on your
Chamberlain, LiftMaster, and Sears Craftsman garage door openers manufactured after 1997 have an amber sensor light on the sending sensor and a green light on the receiving sensor. When the sensors are misaligned, the green light will be off. If they are slightly misaligned, the green receiving sensor light could be slightly flickering if you take a closer look at it. If that is the case they will need to be aligned properly or possibly replaced.
Genie garage door openers use a green light for the sending sensor and a red light for the receiving sensor. When Genie
Linear garage door openers have a green light on the sending sensor and a green and red light on the receiving sensor. The green lights let you know there is power going to the sensors. The red light on the receiving sensor glows bright red when the sensors are aligned properly. Linear
Safety Sensor Wire Could be Damaged

It is very common for safety sensor wiring to get damaged where they are mounted about six inches off the ground. Many people store shovels, rakes, trash cans, and anything else they can fit in the front corners of their garage which usually gets caught on the sensor wiring causing damage. If you are having issues, check to make sure this wire is intact and does not have any areas where you see broken wires.
Chamberlain, LiftMaster, and Sears Craftsman garage door openers manufactured after 1997 will have an amber or yellow light on the sending safety sensor. The light on the sending sensor should always be on even if the sensors are not aligned properly. If this light is not on, there is a damaged wire somewhere or the wires going into the back of the circuit board at the motor head have come loose. Chamberlain, LiftMaster, and Craftsman openers have polarity wiring so you need to make sure to keep the black and white wires lined up properly for the
Genie garage door openers have a green light on the sending sensor. This light should always be on unless it is not getting power. If the green light is off, check the wiring at the sensor and up at the motor head to make sure there is a good connection. Genie is non-polarity wiring so you don’t have to match up white and black on the wiring. The wiring at the motor head has been known to break over time due to vibration. Genie does things a little differently on the receiving sensor by making the red light blink if not properly aligned. By making the light blink they have provided a built in diagnosis that lets you know alignment is off but there is power going to the sensor.
Linear garage door openers are very simple. There should be a green light shining on both
If your house is pre-wired, you might have to remove the cover plate on the wall so you can access the safety sensor wiring connection for the garage door opener. This wiring is low voltage so you can work on it while the garage door opener is plugged in without any issues. Grab the connection point and wiggle it to see if your sensor lights come on. If that doesn’t work, try making new connections on the wires and use electrical tape to keep wires separated so they don’t touch.
Safety Sensors Are Getting Weak
Every garage door opener is equipped with a sending sensor and a receiving sensor. The sending sensor shoots out an invisible beam which needs to make a connection with the receiving sensor in order to complete the circuit which allows the garage door opener to close. These sensors are only active on the down cycle and have no effect on a garage door opener when it is going up.
The most common double car garage door is 16 or 18 feet wide. Over time the sending sensor can get weak making it harder to align the
When purchasing new
The Sun is Shining on Wrong Safety Sensor
If you are having issues closing your garage door when there is a lot of sunlight shining into the garage, you might need to check to see which safety sensor is in the sunlight. Sunlight can cause interference with garage door opener
Safety sensor orientation by brand should be as follows:
- Chamberlain/LiftMaster/Sears sending sensor in the sun (amber light)
- Genie receiving sensor in the sun (red light)
- Linear sending sensor in the sun (green light only)
- Guardian TX-Sender in the sun (green light)
- Marantec sending sensor in the sun (green light)
Safety Sensors Need to Be Installed Properly

- 6 inches off ground
- the proper sensor in the sun
- aligned with track or behind to prevent hitting sensors
If you have multiple garage door openers, you need to make sure your
Snappy Brackets on Chamberlain, LiftMaster, and Craftsman Garage Door Openers
If you are having issues with trying to keep your
You will also need to make sure the vertical tracks are secure to the wall if your
Safety Sensors are Not Designed to Get Wet
If you wash your garage floor or have a rogue sprinkler head spraying toward the garage door when it’s open, your
Can I add Safety Sensors to an older Garage Door Opener?
No. If your garage door opener was manufactured before 1993, your system won’t have
Still having problems closing your garage door?
It could be the down force adjustment on the garage door opener. Garage door openers are equipped with sensitivity/force adjustments that allow the unit to reverse if it comes in contact with something. The force adjustments are tied directly to the circuit board and they can weaken over time. You can increase the down force a notch or two which will make the garage door opener apply more force when closing the garage door. The garage door opener force needs to be tested monthly and after any adjustments are made to the force. The owner’s manual for your garage door opener will illustrate how to perform this test.