Use the emergency release, and reconnect

The cord with a handle, often red, hanging from the opener's rail is the emergency release. Pulling it disconnects the door from the opener, so the door can be lifted by hand: in a power cut, or when the opener has failed. It is simple to use, and it has one serious hazard.

The hazard: the door's weight

When the door is connected to the opener, the opener holds it. When you pull the release, nothing holds it but the springs. If a spring is weak or broken, an open door can come down on its own. Chamberlain's owner's manual:

If possible, use emergency release handle to disengage trolley ONLY when garage door is CLOSED. Weak or broken springs or unbalanced door could result in an open door falling rapidly and/or unexpectedly.

The federal text printed in every residential opener's manual says the same: use the release "only when the door is closed" where possible.

The manual adds two more rules: never pull the release unless the doorway is clear of people and things, and never use the handle to pull the door open or closed.

Before you pull it, look at the springs. A coil above the door with a gap in it, or a slack spring along a track, means the door is not balanced. Do not lift it by hand. See broken spring.

Disconnect (LiftMaster and Chamberlain)

1. With the door fully closed if possible, pull the release handle down until the trolley's release arm snaps to the vertical position.
2. The door can now be raised and lowered by hand as often as needed.

Do not use the release handle to pull the door; lift the door itself.

Reconnect

LiftMaster and Chamberlain. Pull the release handle toward the opener, so the release arm snaps to the horizontal position. The trolley reconnects on the next up or down run, whether you move the door by hand or run the opener from the wall control or a remote.

Genie (chain and belt drive). Genie's programming instructions show the carriage lever, which must be up. Then lift the door by hand until the carriage engages the chain or belt. On some Genie models the troubleshooting guide calls this putting the carriage lever into the lock position.

If the opener runs but the door does not move after a power cut, the door is probably still disconnected. See opener runs, door doesn't.

In a power cut

• An opener with a battery backup keeps working for a while, more slowly and without its light, and you may not need the release at all.
• If you open the door by hand, close it by hand too, and reconnect it once the power is back.

Updated 2026-10-11.