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Home Assistant sensors can turn a condition—water on a floor, someone in a room, or air that is too damp or warm—into a signal an automation can act on. The useful distinction is that a sensor reports what it detects; the resulting action depends on the devices, integrations, and automation you configure.
How a sensor becomes an automation
Home Assistant’s sensor entities can expose values from physical devices, web services, built-in calculations, or custom sensors. A typical automation connects three things: the condition being measured, the entity or event Home Assistant receives, and the action you want it to take. The Home Assistant sensor integration documentation describes sensor entities and their values.
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Before choosing hardware, identify the condition you want to detect and confirm that the device can expose it to your Home Assistant installation. Then check any required hub or radio, power, placement, and the action device the automation would control.
1. Water leaks that are easy to miss
A water leak sensor can report water on a surface as a moisture binary sensor. Home Assistant provides a “Moisture detected” trigger for when a moisture sensor starts detecting water. Its documentation suggests locations such as under a sink, behind a dishwasher, next to a washing machine, or in a basement. See the Moisture detected trigger documentation and the Moisture integration documentation.
#1 Best Overall
- [NOTES] Requires Aqara Zigbee 3.0 hub (Not compatible with other Zigbee hubs). Requires a secured 2.4 GHz Wi-Fi for Hub M2/M1S/E1/M1S Gen2 and Camera Hub G2H Pro/G2H, and 2.4/5 GHz Wi-Fi for Camera Hub G3.(Wired connection via Ethernet RJ45 for Hub M2 is also supported.) The Motion Sensor P1 is compatible with Aqara Home, HomeKit, Alexa, IFTTT, Home Assistant. (*Note: No light sensitivity function in HomeKit and Alexa; Please update hub firmware for optimal use.)
- [5-Year Battery Life] The Zigbee motion sensor boasts an impressive five-year battery life, maintaining reliable performance even in low temperatures or with lightning-fast detection timeouts. The Aqara Motion Sensor P1 dimensions are 1.46"D x 2.17"W x 2.76"H.
- [Configurable Detection Timeout] Easily adjust the Aqara motion sensor timeout without any hardware modifications. Through the Aqara Home app, configure the timeout from 1 to 200 seconds to save energy or capture every movement promptly. Zigbee2MQTT and comparable third-party USB dongles are not officially supported by Aqara. Full product functionality may be limited or unavailable.
- [Adjustable Viewing Angle & Detection Distance] Experience a wide detection range with a 170° field of view up to 4 meters and 150° up to 7 meters. The flexible 360° stand makes it easy to adjust the angle, so the motion sensor only triggers when needed. Choose from three sensitivity levels (high, medium, low) to fine-tune detection distance based on your setup. For a stable connection, ensure the motion sensor is placed within 393 inches (10 meters) of the Aqara Zigbee Hub.
- [Alert System and Home Automations] Set up the Aqara Home Alert System or integrate it with HomeKit and other supported systems for continuous monitoring and local sound, light alarms, and cloud notifications upon motion detection. The Zigbee motion detector seamlessly integrates into smart home automations. Easily configure "IF" and "THEN" smart automations, such as turning on lights via Aqara Smart Wall Switch or powering devices with the Aqara Smart Plug.
That signal can start a response, such as sending a notification. Home Assistant’s documented example also closes a water main valve. The sensor alone cannot shut off water: that response requires a compatible valve, an integration Home Assistant can control, and a correctly configured automation. The example does not establish compatibility between any particular sensor and valve.
2. A room that appears empty when someone sits still
Motion sensing and presence sensing address different needs. A motion sensor reports movement; a presence sensor is intended to represent occupancy beyond momentary movement. Aqara describes its presence-sensing category as detecting moving and non-moving people, but that is a manufacturer description, not independent testing or a guarantee of detection in every room. Aqara also lists water-leak and temperature-and-humidity sensor categories on its sensor page.
Rank #2
- [Precise AI-Powered Presence Sensor] Powered by advanced AI, PIR, and 60GHz mmWave radar, the FP300 accurately detects human presence even when you’re still. Its adaptive AI learning continuously optimizes sensitivity to reduce false triggers, ensuring lights and devices stay on even when you’re lounging on the couch, and off when they need to be.
- [Broad Compatibility] Supports Matter over Thread and Zigbee for seamless integration with major ecosystems. Works with Apple Home, Home Assistant, Alexa, Google Home, SmartThings, and Homey via Matter for flexible, reliable automation. (* For third-party Matter ecosystems, a corresponding Thread Border Router and Matter Controller are required. * For Aqara, a Zigbee 3.0 or Matter hub like M2/M3/G410/etc, except G2H, with the latest firmware is needed.)
- [5-in-1 Multi-Sensor] Combines 60GHz mmWave, PIR, light, temperature, and humidity sensors into one compact device. This all-in-one design enables precise detection of presence and environmental conditions, helping automate lighting, climate control, and security systems for a smarter and more energy-efficient home.
- [Long Battery Life & Energy Efficiency] Powered by two replaceable CR2450 batteries, the FP300 offers up to 3 years of battery life in Zigbee mode or 2 years in Thread mode. Optional sensor deactivation helps conserve energy, ensuring consistent and long-lasting performance. What's Included: FP300 Multi-Sensor × 1, Sticker × 1, User Manual × 1
- [Wire-Free & Flexible Installation] Completely wireless with a multi-axis adjustable mount for easy wall, ceiling, or corner setup. No wiring required—relocate anytime for optimal detection and coverage. Featuring a 120° field of view and up to 6 m (20 ft) of detection range, the FP300 can effectively monitor various room layouts. Its minimalist design blends seamlessly into any modern interior, delivering powerful functionality without visual clutter.
Before buying a presence sensor, verify the exact model’s Home Assistant compatibility, whether it requires a hub or particular radio, its power needs, placement guidance, and any configuration needed to expose the right entity. Do not assume that a category description proves a specific model will work with your setup.
3. Air that is too damp or too warm
A temperature and humidity sensor can provide readings for an indoor-condition automation—for example, using a humidity reading as a condition for controlling a compatible fan or ventilation device. That is a design pattern, not a guarantee of a particular result; the sensor must integrate with Home Assistant, and the device you want to control must also be available to the automation.
Rank #3
- ZIGBEE STANDARD COMPATIBLE MOTION SENSOR: A Zigbee Hub is required. Compatible with Zigbee hubs and Echo devices with built-in Zigbee hubs, including Echo (4th Gen), Echo Plus (1st & 2nd Gen), Echo Studio, Echo Show 8 (3rd Gen), Echo Show 10 (2nd & 3rd Gen), Echo Hub, Eero 6, Eero Pro 6, Home Assistant, SmartThings (2015/2018), Aeotec, Hubitat, Homey Bridge, Homey Pro, and Third Reality Hub Gen2 Plus.
- CREATE ROUTINES: Using the Alexa app, create your own routines that are triggered when motion is detected. Customize Alexa messages like “Welcome Home” or “Motion Detected in Living Room” when motion is detected.
- SMART LIGHT CONTROL: If you have a smart light or smart plug connected to the Alexa service, you can create a routine in the Alexa app that will enable it to automatically turn on when motion is detected (and off when no motion is detected for a period of time that you specify).
- HASSLE-FREE SETUP: Installs in a few seconds. Just make sure device in paring mode and compatible Echo device automatically discovers it by saying “Alexa, discover devices”. Only for indoor use.
- GREAT RANGE AND LONG BATTERY LIFE : Capable of detecting motion up to 20 feet (6 meters) away. 2 AAA batteries can last for 2 years in typical usage.
Airborne humidity is not the same as water on a surface. Use humidity readings to reason about damp air and a moisture binary sensor to detect a leak or other surface water. Home Assistant distinguishes these concepts in its Moisture integration documentation.
Quick Recap
Best Value
- ZIGBEE STANDARD COMPATIBLE MOTION SENSOR: Works with compatible Zigbee hubs or Echo devices with Zigbee hub built-in, such as Echo (4th Gen), Echo Plus (1st Gen and 2nd Gen), Echo Studio, Eero 6, Eero Pro 6, Home Assistant, SmartThings 2015/2018, Aeotec, Hubitat, Homey Bridge, Homey Pro, Third reality Hub and Third Reality Smart Speaker. Zigbee Hub Required.
- CREATE ROUTINES: Using the Alexa app, create your own routines that are triggered when motion is detected. Customize Alexa messages like “Welcome Home” or “Motion Detected in Living Room” when motion is detected.
- SMART LIGHT CONTROL: If you have a smart light or smart plug connected to the Alexa service, you can create a routine in the Alexa app that will enable it to automatically turn on when motion is detected (and off when no motion is detected for a period of time that you specify).
- HASSLE-FREE SETUP: Installs in a few seconds. Just make sure device in paring mode and compatible Echo device automatically discovers it by saying “Alexa, discover devices”. Only for indoor use.
- GREAT RANGE AND LONG BATTERY LIFE : Capable of detecting motion up to 20 feet (6 meters) away. 2 AAA batteries can last for 2 years in typical usage.
Rank #4
- ZIGBEE STANDARD COMPATIBLE MOTION SENSOR: Works with compatible Zigbee hubs or Echo devices with Zigbee hub built-in, such as Echo (4th Gen), Echo Plus (1st Gen and 2nd Gen), Echo Studio, Eero 6, Eero Pro 6, Home Assistant, SmartThings 2015/2018, Aeotec, Hubitat, Homey Bridge, Homey Pro, Third reality Hub and Third Reality Smart Speaker. Zigbee Hub Required.
- CREATE ROUTINES: Using the Alexa app, create your own routines that are triggered when motion is detected. Customize Alexa messages like “Welcome Home” or “Motion Detected in Living Room” when motion is detected.
- SMART LIGHT CONTROL: If you have a smart light or smart plug connected to the Alexa service, you can create a routine in the Alexa app that will enable it to automatically turn on when motion is detected (and off when no motion is detected for a period of time that you specify).
- HASSLE-FREE SETUP: Installs in a few seconds. Just make sure device in paring mode and compatible Echo device automatically discovers it by saying “Alexa, discover devices”. Only for indoor use.
- GREAT RANGE AND LONG BATTERY LIFE : Capable of detecting motion up to 20 feet (6 meters) away. 2 AAA batteries can last for 2 years in typical usage.
Check the complete chain before relying on it
- Confirm the sensing job: surface water, room presence, or air temperature and humidity are separate requirements.
- Check the exact device: verify Home Assistant integration, any hub or radio requirement, power, and recommended placement for the model you are considering.
- Verify the entity or event: make sure Home Assistant receives the state or reading your automation needs.
- Test the action: confirm that the notification, fan, valve, or other controlled device responds as intended before relying on the automation.
- Inspect failures: Home Assistant’s automation troubleshooting guide explains how to inspect a trace and check that the automation still references the correct entity.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
