Heating Off on Open Window – Home Assistant

🌡️ Automatic Room Heating Based on Window State

This guide explains how to set up a smart heating automation in Home Assistant that reacts to your window sensors to maximize comfort and save energy.

Window Opened: The heating in the corresponding room will automatically turn off.
Window Closed: The heating will restore the last manually set temperature for that room.

Use Case: Ideal for homeowners who want to avoid heating a room unnecessarily when windows or doors are open, while maintaining comfort when windows are closed. Each room can have its own automation and temperature memory.

⚙️ Requirements

A working Home Assistant installation
Climate integrations (thermostats) for each room
Binary sensors for windows or doors
Input Number helpers to store the last set temperature

🔧 Setting Up Input Number Helpers

Input Numbers are used to remember the last desired temperature for each room. Example configuration for the living room:

YAML

wohnzimmer_last_temp:
  name: Living Room Last Temperature
  min: 5
  max: 30
  step: 0.1
  unit_of_measurement: "°C"
  initial: 23.5

💾 Automation Example (Per Room)

This automation triggers whenever a window sensor changes state. When the window opens, it stores the current temperature and turns off the heater. When the window closes, it restores the previous temperature.

YAML

alias: Living Room Window Heating Control
trigger:
  - platform: state
    entity_id: binary_sensor.living_room_windows
condition: []
action:
  - choose:
      - conditions:
          - condition: state
            entity_id: binary_sensor.living_room_windows
            state: "on"
        sequence:
          - service: input_number.set_value
            target:
              entity_id: input_number.wohnzimmer_last_temp
            data:
              value: "{{ state_attr('climate.living_room', 'temperature') }}"
          - service: climate.turn_off
            target:
              entity_id: climate.living_room
      - conditions:
          - condition: state
            entity_id: binary_sensor.living_room_windows
            state: "off"
        sequence:
          - service: climate.set_temperature
            target:
              entity_id: climate.living_room
            data:
              temperature: "{{ states('input_number.wohnzimmer_last_temp') | float }}"
mode: single

📄 Notes and Best Practices

Each room should have its own automation with its respective thermostat and window sensors.
Input Numbers store the last manually set temperature, ensuring the system always restores your preferred comfort level.
This approach works with multiple windows per room and automatically reacts to any open or closed state.
You can expand this logic to include doors, guest rooms, or any other zones in your house.
Optional: Combine with Home Assistant presence detection or HVAC schedules for even smarter energy savings.

⚡ Summary

This automation setup ensures:

Energy savings by turning off heating when windows are open.
Comfort restoration by automatically setting the last preferred temperature when windows close.
Scalability: Add as many rooms as you need with separate automations and temperature memory.