Why won't my garage door close?

expert EXPERT June 06, 2007

There are a number of things that could cause the door not to close. Assuming your opener will still raise the door, the most common issues are related to the safety sensors. These sensors keep the door from accidentally closing on something or someone that might be under it. The overhead lights should flash when the door fails to close for this reason.

According to your Manage my Home profile, this opener was purchased in 1992 and at that time the safety sensors were not yet mandatory so this might not apply in your situation. If you do have safety sensors, make sure each sensor has an LED brightly lit on it. No LED indicates damaged wiring to the sensors or a failed sensor. A faint LED indicates poor alignment and should get brighter as the sensors are aligned to "see" each other well enough to allow the door down.

Binding or misalignment of the garage door itself is another common reason for a door opening but not closing. Check the door by releasing the lift mechanism and seeing if you can move the door by hand. If not, the door needs attention. If the opener can move the lift mechanism without the door attached to it then this also indicates the opener is working but the door has a problem.

From there it gets a little more involved, you can check the RPM sensor but you need to unplug the opener and then pull off the opener cover. Check that the plastic cap on the end of the lift motor shaft has not moved too far out. It just slides in place and vibration can move it on the shaft until the control board cannot tell if the door is moving. Just push the cap onto the shaft until it stops.

While under the cover you can also look for any broken of disconnected wires.

If the door still will not lower, it might be time to call a professional as you are now at the point of checking electronic controls that could be easily damaged or shock you if tested incorrectly.