Chamberlain 821LM-SENSOR - User Manual

ONE YEAR LIMITED WARRANTY
LiftMaster, Inc. warrants to the fi rst retail purchaser of this product
that is free from defect in materials and/or workmanship for a
period of 1 year from the date of purchase.
NEED HELP?
Go to the Help section at www.myliftmaster.com, or call LiftMaster
Technical Support at 1-800-528-9131.
INSTALL THE DOOR SENSOR
1. Position the door sensor vertically and attach to a clean, dry
location on the top panel of the garage door with fastening
strips (provided).
OR
Press in the bottom of the door sensor and remove the front
cover. Position the door sensor vertically and attach to the top
panel of the garage door with screws (provided). Replace the
front cover.
PROGRAM THE DOOR SENSOR
1. Use the MyQ
®
App to add a new door sensor.
OR
1. Press and release BUTTON 1 for door 1 or BUTTON 2 for door
2 on the Wi-Fi hub. The yellow LED on the Wi-Fi hub will turn
off when successfully programmed.
2. Press the Test button on door sensor until the yellow LED on
the door sensor turns on.
3. Press the Test BUTTON again on the door sensor and the Wi-Fi
hub will beep once for door 1 and twice for door 2.
BUTTON
(Settings)
BUTTON 1
BUTTON 2
LED
Front
Cover
Screws
Test BUTTON
Top Panel
of Garage Door
Top Panel
of Garage Door
Fastening
Strips
Door
Sensor
Wi-Fi Hub
Top
OR
NOTICE: To comply with FCC and/or Industry Canada (IC) rules, adjustment or modifi cations
of this transceiver are prohibited. THERE ARE NO USER SERVICEABLE PARTS.
This device complies with Part 15 of the FCC rules and IC RSS-210. Operation is subject to
the following two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may cause
undesired operation.
To prevent possible SERIOUS INJURY or DEATH from a closing
garage door:
• Activate door ONLY when it can be seen clearly, is properly
adjusted, and there are no obstructions to door travel.
• ALWAYS keep garage door in sight until completely closed
NEVER permit anyone to cross the path of closing garage
door.
Door Sensor
Models 821LM-SENSOR and 041D7924-1
LiftMaster
845 Larch Avenue
Elmhurst, IL 60126-1196
1-800-528-2806
www.liftmaster.com

Summary

Install the Door Sensor

Install with Fastening Strips

Attach the door sensor vertically to a clean, dry location on the top panel of the garage door using fastening strips.

Install with Screws

Press the bottom of the door sensor, remove the front cover, attach vertically to the garage door top panel with screws, and replace the cover.

Program the Door Sensor

Program via MyQ App

Use the MyQ® App to add a new door sensor to your system.

Program via Wi-Fi Hub Buttons

Press Wi-Fi hub buttons, then test sensor button until programming is confirmed by LEDs and beeps.

Safety Warnings

Closing Garage Door Hazards

To prevent serious injury or death, activate door only when visible and clear of obstructions. Always supervise.

One Year Limited Warranty

Need Help?

Chamberlain 821LM-SENSOR Specifications

General

Type	Garage Door Sensor
Connectivity	Wireless
Power Source	Battery
Color	White
Features	Monitors garage door position, alerts if left open
Installation	Easy DIY installation