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Zigbee devices Water leak sensors

Bosch BSEN-W

Water alarm (formerly known as BWA-1). Works with Zigbee2MQTT with no vendor hub or cloud: it pairs with a Zigbee stick and shows up in Home Assistant.

Vendor
Bosch
Model
BSEN-W
Type
Water leak sensors
Power
battery: an end device, does not extend the mesh
Firmware updates (OTA)
yes, through Zigbee2MQTT

Find it in shops: AliExpress

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What it exposes

FeaturePropertyValuesControl
Water leakwater_leak—read only
Tampertamper—read only
Mute water leak alarmwater_leak_alarm_control—settable
Alarm on motionalarm_on_motion—settable
Test modetest_mode—settable
Test mode timeouttest_mode_timeoutseconds · 1…255settable
Batterybattery% · 0…100read only
Low batterybattery_low—read only

MQTT: state and commands

Zigbee2MQTT publishes the device state to zigbee2mqtt/my_device (my_device is the name you give the device). An example message:

{
  "water_leak": false,
  "tamper": false,
  "water_leak_alarm_control": false,
  "alarm_on_motion": false,
  "test_mode": false,
  "test_mode_timeout": 128,
  "battery": 87,
  "battery_low": false,
  "linkquality": 120
}

Send commands to zigbee2mqtt/my_device/set:

mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"water_leak_alarm_control":true}'
mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"alarm_on_motion":true}'
mosquitto_pub -t zigbee2mqtt/my_device/set -m '{"test_mode":true}'

Watch the topics live from the browser: MQTT client.

Home Assistant automation example

Zigbee2MQTT creates Home Assistant entities from the device name. If it is called my_device, an automation in automations.yaml can look like this:

- alias: "Water leak"
  mode: single
  triggers:
    - trigger: state
      entity_id: binary_sensor.my_device_water_leak
      to: "on"
  actions:
    - action: notify.notify
      data:
        message: "Water leak detected!"

Check the YAML: YAML checker.

How to pair it

  1. In Zigbee2MQTT click Permit join.
  2. Put the device in pairing mode: usually a long press of the reset button (5–10 s) until the LED blinks; bulbs: switch the power off and on 5–6 times.
  3. Keep the device close to the coordinator or a router while pairing.
  4. Give it a clear name: MQTT topics and Home Assistant entities are built from it.

Exact procedure and model notes: the device page in the Zigbee2MQTT docs. No coordinator yet: coordinator picker.

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