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Sensor House

Sensor House

Leak and freeze plan builder

Tick what your house has. Get every leak and freeze sensor it needs, where each one goes, and the automations to run them, ready to copy.

This is Leak and Freeze's plan builder, the same engine, here so it can be put on another site. Tell it what your house has and it lists a leak sensor for every place water can start, a temperature sensor for every space the furnace does not heat, whether an automatic shutoff valve is worth it, and three automations for exactly those sensors: wet, below 40 degrees, and silent for 24 hours. It runs in your browser and sends nothing.

Your house

Runs in your browser. Nothing you pick is sent.

  • 9 leak sensors
  • 1 freeze sensor
  • Yes shutoff valve

Leak sensors 9

  1. Water heater. On the floor beside the tank, under the drain valve and the relief valve's pipe. binary_sensor.water_heater_leak Why
  2. Washing machine. On the floor behind the machine, where the supply hoses meet the wall valves. binary_sensor.washer_leak Why
  3. Dishwasher. Under the sink beside it, where its supply line and drain hose connect. binary_sensor.dishwasher_leak Why
  4. Sink 1. On the cabinet floor under the sink, below the shutoff valves and the trap. binary_sensor.sink_1_leak Why
  5. Sink 2. On the cabinet floor under the sink, below the shutoff valves and the trap. binary_sensor.sink_2_leak Why
  6. Sink 3. On the cabinet floor under the sink, below the shutoff valves and the trap. binary_sensor.sink_3_leak Why
  7. Toilet 1. On the floor behind the bowl, under the supply line. binary_sensor.toilet_1_leak Why
  8. Toilet 2. On the floor behind the bowl, under the supply line. binary_sensor.toilet_2_leak Why
  9. Air conditioner drain pan. In or beside the furnace's condensate pan, or under the condensate pump. binary_sensor.ac_drain_leak Why

Freeze sensors 1

  1. Pipes on an outside wall. Inside the sink cabinet on the outside wall, near the pipes. sensor.exterior_wall_temperature Why

Automatic shutoff valve

  • With 9 leak sensors, one valve on the main answers every one of them.

automations.yaml

Download
- alias: "Leak: a sensor is wet"
  mode: single
  triggers:
    - trigger: state
      entity_id:
        - binary_sensor.water_heater_leak
        - binary_sensor.washer_leak
        - binary_sensor.dishwasher_leak
        - binary_sensor.sink_1_leak
        - binary_sensor.sink_2_leak
        - binary_sensor.sink_3_leak
        - binary_sensor.toilet_1_leak
        - binary_sensor.toilet_2_leak
        - binary_sensor.ac_drain_leak
      to: "on"
  actions:
    - action: valve.close_valve
      target:
        entity_id: valve.main_water
    - action: notify.notify
      data:
        title: "Water detected"
        message: "{{ trigger.to_state.name }} is wet. The main water valve is closing."

- alias: "Freeze: a space is below 40 F"
  mode: single
  triggers:
    - trigger: numeric_state
      entity_id:
        - sensor.exterior_wall_temperature
      below: 40
      for:
        minutes: 15
  actions:
    - action: notify.notify
      data:
        title: "Freeze risk"
        message: "{{ trigger.to_state.name }} is at {{ trigger.to_state.state }} degrees. Open the cabinet doors and let a faucet drip."

- alias: "Watch: a water sensor went quiet"
  mode: queued
  triggers:
    - trigger: state
      entity_id:
        - binary_sensor.water_heater_leak
        - binary_sensor.washer_leak
        - binary_sensor.dishwasher_leak
        - binary_sensor.sink_1_leak
        - binary_sensor.sink_2_leak
        - binary_sensor.sink_3_leak
        - binary_sensor.toilet_1_leak
        - binary_sensor.toilet_2_leak
        - binary_sensor.ac_drain_leak
        - sensor.exterior_wall_temperature
        - valve.main_water
      to: "unavailable"
      for:
        hours: 24
  actions:
    - action: notify.notify
      data:
        title: "A water sensor is offline"
        message: "{{ trigger.to_state.name }} has not reported for 24 hours. Check its battery."

Rename each entity to match your own devices, then paste. Syntax: Home Assistant: Automation triggers.

The builder is Leak and Freeze's, and so are the guides behind each sensor: the builder on Leak and Freeze. To put it on your own site, see the widgets.

Sources

  1. IBHS: State of the Risk, Interior Water Damage (white paper, December 2024) Insurance Institute for Business and Home Safety
  2. American Red Cross: Preventing and thawing frozen pipes American Red Cross
  3. Home Assistant: Binary sensor (device classes moisture, door, garage door, battery) Home Assistant
  4. Home Assistant: Automation triggers Home Assistant
  5. Home Assistant: Valve (valve.close_valve) Home Assistant

Drafted with a language model on October 26, 2026 from the sources listed above. Every recipe on the page is written by the site's own code and parsed by a test. The editor samples pages after they publish; nothing here is advice from a licensed electrician or plumber.

Found an error? See Corrections.

Leak and freeze plan builder | Sensor House