Inconsistent error handling on fan entity when turning fan off

The problem

On a fan entity that does not implement FanFeature.TURN_OFF a service error is raised if the on/off switch is clicked:

2024-11-20 10:47:05.120 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection] [546352226240] Unexpected exception
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py", line 245, in handle_call_service
    response = await hass.services.async_call(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2802, in async_call
    response_data = await coro
                    ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2845, in _execute_service
    return await target(service_call)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 989, in entity_service_call
    raise HomeAssistantError(
homeassistant.exceptions.HomeAssistantError: Entity fan.e3_vitopure_ventilation does not support this service.

This also gives a proper error message saying that the service is not supported.

However when setting the speed to 0 via the slider an unknown error occurs as the async_turn_off method is called directly.

2024-11-20 10:46:48.689 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection] [546352226240] Unexpected exception
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py", line 245, in handle_call_service
    response = await hass.services.async_call(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2802, in async_call
    response_data = await coro
                    ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/core.py", line 2845, in _execute_service
    return await target(service_call)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 1007, in entity_service_call
    single_response = await _handle_entity_call(
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/service.py", line 1079, in _handle_entity_call
    result = await task
             ^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/fan/__init__.py", line 343, in async_set_percentage
    await self.async_turn_off()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1695, in async_turn_off
    await self.hass.async_add_executor_job(ft.partial(self.turn_off, **kwargs))
  File "/usr/local/lib/python3.12/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 1691, in turn_off
    raise NotImplementedError
NotImplementedError

What version of Home Assistant Core has the issue?

2024.11.2

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

No response

Link to integration documentation on our website

No response

Diagnostics information

No response

Example YAML snippet

No response

Anything in the logs that might be useful for us?

No response

Additional information

No response

Hey there @home-assistant/core, mind taking a look at this issue as it has been labeled with an integration (fan) you are listed as a code owner for? Thanks!

Code owner commands

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home-assistant / core