Garage Door Won't Close
Chamberlain Garage Door Opener
Severity:What Does This Error Mean?
A Chamberlain garage door that will not close — either reversing immediately or stopping partway — is almost always caused by the photo-eye safety sensors being misaligned or obstructed. The door is designed to stop and reverse if the sensor beam is broken. Aligning the sensors until both LEDs are solid (not blinking) is the fix for most cases.
Affected Models
- Chamberlain B970
- Chamberlain B6765
- Chamberlain myQ series
- LiftMaster 8500 series
- Most Chamberlain and LiftMaster models
Common Causes
- Safety sensors misaligned — door reverses as a safety response
- Something blocking the sensor beam at floor level
- Down travel limit set incorrectly — opener stops before the door reaches the floor
- Door track obstructed or something jamming the door mechanism
- Remote transmitter needs battery replacement or reprogramming
How to Fix It
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Check the safety sensors first — look at the two sensor units near the floor on each side of the door. Both LEDs should be solid (not blinking). A blinking LED means misalignment.
See the Sensor Obstruction guide for detailed alignment steps. Misaligned sensors are the cause of more than 80 percent of doors that will not close.
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If sensors are aligned and solid, check for any physical obstruction in the door track — a tool, debris, or a bent track section that the door catches on.
Walk along both sides of the door track and inspect for anything blocking the rollers or panels. A bent track can prevent full closure and requires straightening or professional repair.
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Test the wall button. If the door closes with the wall button but not the remote, the remote battery needs replacing or the remote needs reprogramming.
To reprogram a Chamberlain remote: press the Learn button on the motor unit, then press the remote button within 30 seconds until the motor unit light blinks twice.
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If the door closes partway then reverses, the down travel limit may need adjustment. Locate the Down limit adjustment screw on the motor unit and turn it clockwise in small increments.
The limit adjustment screw is labelled Down or has a downward arrow. Turn it slowly — each half-turn moves the stop point by approximately 5 centimetres.
Frequently Asked Questions
Why does the garage door close at night but not during the day?
This is almost always caused by afternoon sunlight hitting the receiving safety sensor and blinding it. The sun's position changes through the day, so the issue may only occur at certain hours. Shading the sensor with a small cardboard visor taped above it fixes this.
Is it safe to close the garage door manually if the opener won't close it?
Yes — pull the red emergency release cord to disconnect the door from the opener, then pull the door down manually. This bypasses the opener completely and lets you secure the garage while you troubleshoot.