On and off switch for Heat Control thermostat

This feature request might be for all thermostats, but I only have the Heat Control so I don’t know for the rest.
I would like to have a switch to turn the thermostat on and off.

Have you try with an input_boolean ?
in adding this input_boolean in automations like this example

in configuration.yaml

    name: Chromecast lumieres
    initial: on
    icon: mdi:spotlight-beam

and in automations.yaml

  - alias: "Chromecast paused/stopped"
      - platform: state
        entity_id: media_player.chromecast2
        from: 'playing'
      - condition: state
        entity_id: input_boolean.cast_light
        state: 'on'
        service: scene.turn_on
        entity_id: scene.Allume

the scene Allume turn on only if the switch “cast_light” is on …