Turn switch on when connection to Home Assistant is lost

ESPHome
1

Hello,

I use two ESPHome-controlled relays to control my heat pump. I would like to implement automatic fallback logic that turns the heating on if Home Assistant is offline for more than 30 minutes.

I accomplished something similar on a Shelly 2PM by sending a REST command from Home Assistant to the Shelly every minute to reset a timer on the device. If the reset command is missed for more than a certain number of minutes, the device performs a specific action (in this case, retracting an awning).

How can I accomplish something similar with ESPHome?

Thank you!

2

Maybe just call an ESPHome action from HA?

3

I’m sure there are many ways to do that, which one is best, I don’t know.
One way could be status binary sensor with timer script.
Something like:

binary_sensor:
  - platform: status
    id: ha_connected
    on_release: # when HA disconnects
      then:
        - script.execute: fallback_timer
    on_press: #when HA reconnects
      then:
        - script.stop: fallback_timer
1 Like
4

I use a number of sensors in my heating controller that fallback to a local sensors or a fixed value if the ESP module loses connection to HA.

  - platform: template # Sets Heat schedule to ON if Homeassistant not available and connected
    name: "${friendly_name} CH Schedule"
    id: heat_schedule
    lambda: |-
      if (id(connected).state) {
        return id(ha_heat_schedule).state;
      } else {
        return "on";
      }

Hopefully you cn see how this works.

5

Another approach might use the api.connected condition which checks if at least one client is connected to the ESPHome native API.

Possibly check api.connected in an api.on_client_disconnected trigger, and if it was the last connection start a timer. api.on_client_connected trigger can reset the timer since there must now be some connection.

6

Thank you to all of you for pointing me in the right direction!

I went with @Karosm suggestion because it seemed easier to implement a delay. This is my solution with the help of Grok:

globals:
  - id: saved_heating_state
    type: bool
    initial_value: 'false'
  - id: fallback_active
    type: bool
    initial_value: 'false'

binary_sensor:
  - platform: status
    id: ha_connected
    on_release:  # HA disconnected → start fallback
      then:
        - script.execute: fallback_timer
    on_press:     # HA reconnected → stop and restore
      then:
        - script.stop: fallback_timer
        - script.execute: restore_heating_state

script:
  - id: fallback_timer
    mode: single
    then:
      - delay: 240min
      - logger.log:
          level: WARN
          format: "HA offline for 240min - activating fallback heating"
      - globals.set:
          id: saved_heating_state
          value: !lambda "return id(heizanforderung).state;"
      - logger.log:
          level: WARN
          format: "Previous state of heating request saved: %s"
          args: [ "id(heizanforderung).state ? \"ON\" : \"OFF\"" ]
      - globals.set:
          id: fallback_active
          value: 'true'
      - switch.turn_on: heizanforderung
      - logger.log:
          level: WARN
          format: "Heating request turned ON because Home Assistant is offline"

  - id: restore_heating_state
    mode: queued
    then:
      - if:
          condition:
            lambda: 'return id(fallback_active);'
          then:
            - logger.log:
                level: WARN
                format: "HA back online - restoring previous heating request state"
            - if:
                condition:
                  lambda: 'return id(saved_heating_state);'
                then:
                  - switch.turn_on: heizanforderung
                  - logger.log:
                      level: WARN
                      format: "Heating request restored: ON"
                else:
                  - switch.turn_off: heizanforderung
                  - logger.log:
                      level: WARN
                      format: "Heating request restored: OFF"
            - globals.set:
                id: fallback_active
                value: 'false'
          else:
            - logger.log:
                level: WARN
                format: "HA came back online before timeout - no fallback heating activated."