The LiftMaster 821LMC-Sensor is a wireless door-position sensor designed specifically for the LiftMaster myQ Smart Garage Hub model 821LMC. It reports the open/closed status of a garage door to the myQ app, enabling real-time monitoring, activity history, and smartphone alerts. Use it as a replacement sensor for a door already linked to your 821LMC hub or as an additional door sensor when you want the same hub to monitor a second garage door. One myQ door sensor is required per garage door, and the myQ Smart Garage Hub connects to your home’s Wi‑Fi to deliver remote access and notifications.
This battery-powered sensor mounts directly to the garage door and pairs through the myQ app with on-screen setup prompts. Installation is straightforward: attach the sensor to the top panel of the door in an upright orientation and complete pairing within the app; no wiring to the opener is needed. The 821LMC-Sensor is intended for residential myQ systems and is not a safety reversing device; it does not replace photo-eye sensors required by UL/CSA standards. For best results, verify you are using an 821LMC Smart Garage Hub with a 2.4 GHz Wi‑Fi network and add one sensor per door you want to monitor. Compatibility, setup steps, and operating details should be confirmed with LiftMaster’s published myQ documentation for your specific hub model.
