How to turn a switch off if it is running more than 10 minutes after a HA restart

[FutureTense]

Ordinarily, this should be pretty simple, as follows:

  trigger: 
    entity_id: switch.homeseer_switch_mba_fan
    platform: state
    to: 'on'
    for:
      minutes: 2

But what happens if HA is rebooted while the fan was on?

[tom_l]

switch.homeseer_switch_mba_fan last_changed and switch.homeseer_switch_mba_fan last_updated should be reset when home assistant starts. So it should trigger 2 minutes after HA starts.

[FutureTense]

Unfortunately, that’s not happening for me. What is the syntax for reading last_changed and last_updated?

[tom_l]

states.entity_id.last_changed

And I see why my advice was wrong. Here’s how I actually stop my dehumidifier:

- id: lounge_dehumidifier_max_runtime_stop
  alias: 'Lounge Dehumidifier Max Runtime Stop'
  initial_state: true
  trigger:
    platform: template
    value_template: "{{ (as_timestamp(strptime(states('sensor.date_time'),'%Y-%m-%d, %H:%M')) - as_timestamp(states.switch.lounge_dehumidifier.last_changed) ) / 3600 > states('input_number.lounge_dehumidifier_run_time') | float }}"

This will stop at the run time specified in the input_number (in hours), either after it has been on that long or that long after a HA restart.

I’m going to improve it according to this advice, so that restarts don’t affect the run time:

Timer since i've pressed a button

The problem you may run into is HA restarts. I think it would be better to save a timestamp in an input_number (whose value will be restored across restarts) when you activate the switch. Then you can tell how long it has been by subtracting that from the current timestamp. The details will probably depend on exactly what you’re trying to do, since your description is somewhat vague. E.g.: - alias: record time when switch is activated trigger: platform: state entity_id: switch.xyz …

[123 (Taras)]

This:

for:
  minutes: 2

behaves as a timer. According to your trigger, switch.homeseer_switch_mba_fan must change to on and remain in that state for at least 2 minutes for the trigger to occur. The key here is that the 2-minute countdown starts at the moment the fan’s state changes to on.

Let’s assume the 2-minute countdown is underway. At around 90 seconds, you restart Home Assistant. Upon restart, the 2-minute timer is also reset, not restarted, but reset. That 90 seconds of elapsed time is reset to 0 after the restart.

In addition, after the restart, the trigger won’t do anything until the fan’s state changes to on. If the fan is already on after the restart, the trigger will never start the 2-minute countdown timer. It will only do so if the fan’s state changes to on (so turned off first then turned on).