A common cause of a malfunctioning garage door sensor is lack of power supply.
Sensors garage door not working.
The sensors have to be aligned with each other and also have to be connected correctly to the garage door system in order to work.
If the batteries in your transmitter are dead the transmitter won t be able to send a signal to your garage door to open.
Two possible problems can lead to a garage door reversing before it even touches the floor.
The transmitters remotes will not work to close the garage door.
You will find that the door will only move an inch or so in the close direction and reverse.
If you find the lights turned off in one or both the sensors it indicates that there is a problem in power supply.
Garage door opener safety sensors can go bad due to age excess sun or water exposure or from physical damage caused by lawn tools bicycles and trash cans that have been repeatedly hitting the sensors.
According to liftmaster issues with the safety sensor wiring typically occur because of a poor connection incorrectly connected wires or a short in the wire from a staple.
This may sound obvious but your garage door transmitters need power to work.
In most cases you can troubleshoot the system and correct the cause of problems.
First check to see if the transmitter on the wall inside your garage still opens your garage door when pressed.
Garage door openers have an adjustment screw that controls the closing force the pressure with which a door is allowed to descend before the motor switches off.
Inspect each sensor to make sure the green or red power indicator lights are.
If they re turned on in both the sensors then there is no issue with the power supply.
If any object blocks the path of the infrared sensors the garage door opener will not activate or will reverse if operating.
Garage doors may display a variety of symptoms if sensors need attention.
Raise the garage door using the control button on the garage wall or the remote control unit from a vehicle.
Press the button that closes the garage door on the garage wall or on your remote.
If the sensors are working the garage door should immediately stop closing and return to the open position.
Look for small led lights on the sensors.
Luckily you can set most automatic garage doors to a manual mode to bypass the sensors.
You can also disconnect the sensors altogether but doing this will prevent most garage doors from working.