Review : Aqara Water Leak Sensor

Back in 2021 when we moved house, we found multiple water leaks in loft areas or behind kitchen cabinets that had been left by the previous owner. Some of these were easily fixed, but it left a lingering feeling that I needed to keep these areas monitored. I didn’t want to have to remove panels or open loft areas regularly, so began the search for a leak detector.

I settled on the Aqara Water Leak Sensor due to its Zigbee integration, easily interfacing with Home Assistant through either ZHA to Zigbee2MQTT.

NOTE : This review will not cover native Aqara integration with their Aqara Hub. Instead I will cover integration via my Conbee II stick into Home Assistant via ZHA. In the future I will update this review based on findings with Zigbee2MQTT.

Aqara Water Leak Sensor Physical Size

The Aqara Water Leak Sensor came out smaller than expected, around the size of a large coin at 50mm diameter and 15mm high. The device has a small lip on the bottom allowing it to be partially submerged before impacting the electrics and battery of the sensor.

The sensor itself is IP67 compliant, rating it as dust proof and fully submersible up to 1m of water. Given how the battery loads from the bottom I wouldn’t want to test this device being submerged for an extended period of time, but considering its main function is to detect water this rating is to be expected.

The sensor is made from a plastic construction, with the top containing a droplet icon sitting on top of a button and status LED. The bottom hides the battery compartment alongside two hex screws that act as the leak detection points. These can apparently be lengthened or extended with wire, but in my testing I have found this to be unnecessary. The plastic overall feels solid, but the flexible top, which is required to press the button does feel flimsy. In the long term I’m not sure this plastic would survive a sustained about of direct sunlight.

Sensor Water Detection

Water detection is performed by contact with water across the bottom two hex bolts. As mentioned above, these can be extended using wires to reach additional places or keep the sensor out of harms way. This relatively primitive method appears to work well with alerting being near instant, my only criticism being that it can take up to 10 seconds to reset once being triggered. Although given its expected use case it is unlikely you’ll be wanting this to trigger at all.

Aqara Water Leak Sensor Other Features and Benefits

As with many Zigbee devices, the Aqara Water Sensor / Leak Detector also reports its own device temperature. This is a feature that could be useful if you’re looking to deploy this in an out building or roof space that may be impacted by extreme temperatures.

In testing I found this to be mostly reliable, however its reporting speed is not instant. Instead, requiring the device to either detect a leak, which is instant, or check in to report the temperature, which can take up to 50-60 minutes. The temperature reading was accurate within 3 degrees amount.

Integration into Home Assistant

As expected for a battery Zigbee device, the Aqara Leak Sensor reports itself as an “EndDevice” to ZHA, meaning it cannot act as a router for other Zigbee devices. This is to be expected as acting as a router would run your battery down fairly quickly, but does mean you need to consider a bulb or other Zigbee device placements to ensure this is near a device in your house.

This highlighted one of the main problems I’ve had with the Aqara Leak Detector in my long term testing. Two, out of three of my sensors would frequently disconnect for days at a time, not ideal for something like a water leak that needs to be dealt with urgently. Frustratingly it wasn’t the furthest devices that would disconnect (in fact – one of them was very close to the Conbee II stick), which did not aid in troubleshooting this issue.

I’ve eventually traced this behaviour to a quirk of the Aqara sensors. This is well documented on Reddit and other forums, but overall Aqara sensors are not reliable at re-routing through the Zigbee network in the event of a disconnection. This meant in practice I would connect the sensor directly to the co-ordinator (Conbee II), move the sensor into position and it would disconnect ~2-3 hours later.

I resolved this by using ZHA’s less well known “Add Devices via this Device” to force a routing, but it took multiple tries and a timeout of around 30 minutes for this re-connection to be successful and picked up by Home Assistant. Since then – these have been solid and I’ve not suffered any disconnections, but this is worth considering when you set these up in your home (especially if your home is large and requires repeaters).

Conclusion