Sometimes the sensors will be in alignment and just as the door gets close to being shut it will vibrate enough to push one sensor off.
Residential garage door goes down but goes back up unexpectedly.
Examine the garage door opener button.
A careless or rushed parking job can cause the car s bumper to block the sensor.
But changes in weather conditions can causes your garage door components to shift or contract.
Your limit switch needs to be adjusted.
When that happens the distance your garage door needs to travel may change.
To troubleshoot the garage door opener button make sure it s clean and free of debris.
But when the door begins to descend all on its own the problem may point to the opener s logic board or the circuitry inside the motor unit itself.
It all depends on the configuration but you likely have a button that activates the door operator.
Garage doors have many parts that all work together including safety features.
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The door operator button is similar to a door bell.
If these can t see each other when the door is almost shut it will send a signal to the garage door motor to open back up.
The button can easily get dirty and stuck in the pushed position.
These garage doors have sensors near the ground to ensure nothing gets stuck underneath the door when it closes.
When a garage door descends on command but then immediately reverses itself the problem is usually with the sensor eyes along the side tracks or with the door s wheels binding in their tracks.
If the door goes up seemingly on its own after you close the door be sure to check for any debris the sensor is picking up.
This is almost always the result of a dirty or obstructed safety feature.
It goes partway down reverses direction and goes back up again.