Aqara Motion Detection Not Working? Troubleshooting Guide
An Aqara motion sensor is a key component in a smart home, used for everything from security alerts to automated lighting. When it fails to detect motion or trigger automations, it can disrupt your entire smart home ecosystem. These issues typically arise from problems with the battery, its placement, or its connection to the Aqara Hub. This guide will help you systematically identify and fix the problem.
### Step 1: Check the Sensor's Battery and Physical State
Before diving into apps and hubs, let's start with the sensor itself.
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Verify Battery Level: The most common reason for an Aqara sensor to become unresponsive is a depleted battery.
- Open the Aqara Home app and navigate to the motion sensor's device page.
- The battery level should be displayed there. If it is low or critical, replace the CR2450 coin battery.
- A low battery can cause the sensor to work intermittently before it stops completely.
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Test the Connection: The sensor has a small reset/pairing button on its side. Press this button once. The LED light on the front should blink. This blink indicates that the sensor is powered on and is trying to communicate with the hub. If the light does not blink at all, the battery is likely completely dead.
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Inspect the Sensor's Lens: The white, domed part of the sensor is the PIR lens. Ensure it is clean and not obstructed by dust, dirt, or physical objects. A blocked lens cannot detect the infrared changes caused by movement.
Step 2: Placement and Environmental Factors
The performance of a Passive Infrared (PIR) sensor is highly dependent on its environment.
- Avoid Heat Sources: PIR sensors work by detecting changes in thermal energy. Do not place the sensor pointing directly at or near heat sources like radiators, air conditioning units, heat vents, or even appliances that get warm. This can lead to false triggers or cause the sensor to miss genuine motion.
- Avoid Direct Sunlight: A spot where direct sunlight falls on the sensor can also cause issues. The rapid warming from the sun can blind the sensor, preventing it from detecting a person walking by.
- Clear Line of Sight: Ensure the sensor has a clear, unobstructed view of the area you want to monitor. Large pieces of furniture, plants, or even glass can block or interfere with its detection capabilities.
- Optimal Placement: For best results, place the sensor about 2 metres (6.5 feet) high on a wall or shelf, angled slightly downwards. This gives it a good vantage point to detect movement across its field of view rather than movement directly towards it.
Step 3: Hub Connectivity and App Configuration
The motion sensor is a Zigbee device and relies entirely on its connection to an Aqara Hub.
### Check the Hub Status
- Is the Hub Online?: In the Aqara Home app, check the status of your Aqara Hub (e.g., M2, M1S, G2H). If the hub itself is offline, none of its connected child devices, including the motion sensor, will function. If the hub is offline, try power cycling it by unplugging it, waiting 30 seconds, and plugging it back in.
- Check Zigbee Range: The sensor needs to be within the Zigbee range of the hub or another powered Zigbee device that acts as a repeater (like the Aqara Smart Plug). If the sensor is too far away or there are many thick walls in between, the signal may be too weak. Try moving the sensor closer to the hub temporarily to see if the connection becomes stable.
### Review Automations and Sensor Timeout
- Check Your Automations: If the sensor is meant to trigger an automation (like turning on a light), double-check the automation's rules in the Aqara app. Ensure it is enabled and that the conditions are set up correctly.
- Understand the Timeout Period: The Aqara motion sensor has a default timeout of 60 seconds. After it detects motion, it will not report a new motion event for one minute. This is to prevent a flood of notifications. If you are testing the sensor by walking back and forth in front of it, you might simply be within this timeout period. Wait for at least two minutes between tests to get an accurate result. Some advanced users modify the sensor's hardware to change this timeout, but for most, it is a fixed delay.