Chamberlain 841LM - User Manual

AUTOMATIC GARAGE DOOR LOCK
Model 841LM
Before you begin
Installation
For use on Residential Garages with an Entry Door Only. Install On Sectional Doors with Torsion
Assemblies Only. This product is intended for installation only by trained garage door technicians.
Please read and save these instructions with the instruction manual of the garage door opener.
Up to two locks can be installed per compatible garage door opener.
This automatic garage door lock is compatible with LiftMaster
®
garage door openers with a
Security Shield.
Carton Inventory: Automatic Garage Door Lock, Template, 1/4"-20x1/2" Screws (2), 33' (10 m) Wire
Tools needed: Stepladder, Drill, 5/16" and 3/4" Drill Bits, Tape Measure, Screwdriver
UNPLUG THE GARAGE DOOR OPENER AND DISCONNECT THE BATTERY (IF APPLICABLE)
BEFORE PROCEEDING. REMOVE ANY MANUAL LOCKS FROM THE GARAGE DOOR.
FOR WALL MOUNT GARAGE DOOR OPENERS CONSULT THE GARAGE
DOOR OPENER MANUAL FOR INSTALLATION STEPS.
Attach template (provided) to track.
TIP: The second roller from the bottom is ideal for
most installations.
Drill holes as marked on template.
Fasten automatic garage door lock to the outside of
the garage door track with the 1/4"-20x1/2" screws.
Run wire (provided) from automatic garage door
lock to garage door opener. Use insulated staples
(not provided) to secure wire in several places.
NOTE: If you are going to cut the wire you will
need to reconnect wire using a wire nut. Do not
tape the ends together. The lock is polarized and
requires you reconnect black to black and white to
white wires.
Plug the connector into one of the lock terminals
on the garage door opener.
NOTE: To install a second automatic garage door
lock, repeat installation steps on the opposite side
of the garage door.
To prevent possible SERIOUS INJURY or DEATH from a closing gate or door:
• Automatic Garage Door Lock MUST be installed per the owner’s manual.
• Be sure to DISCONNECT ALL ELECTRIC AND BATTERY POWER to the garage door opener
BEFORE installing the garage door lock.
• The door MUST be in the fully opened or closed position BEFORE installing the garage door lock.
• Be sure to DISASSEMBLE and REMOVE any manual door locks that might be currently installed.
1
2
3
4
5
Approx. 3"
(7.6 cm)
Lock
terminals
1
2
3
4
5
™
WARNING: This product can expose you to chemicals including lead, which are known to
the State of California to cause cancer or birth defects or other reproductive harm. For more
information go to www.P65Warnings.ca.gov

Summary

Before You Begin

General Safety Warnings

Crucial safety warnings and precautions for installation and operation.

Preparation and Compatibility

Ensure compatibility and follow initial setup steps before installation.

Installation Steps

Attach Template and Drill Holes

Position template and drill pilot holes on the track.

Mount Automatic Garage Door Lock

Secure the lock to the garage door track using screws.

Wire Lock to Opener

Connect the lock's wire to the garage door opener.

Connect Lock Connector

Plug the lock wire connector into the opener's lock terminals.

Operation Modes

Typical Operation

How the lock functions during normal automatic door cycles.

Manual Operation

Procedures for manual release and disconnection of the lock.

Troubleshooting Common Issues

Door Not Opening Completely

Diagnosing issues when the garage door fails to open fully.

Lock Not Activating

Troubleshooting why the automatic lock does not engage or disengage.

Opener Power Failure Impact

How the lock behaves and operates during power outages.

Warranty Information

Chamberlain 841LM Specifications

General

Brand	Chamberlain
Model	841LM
Category	Door locks
Language	English