The major issue with using the official smart home monitor feature, and it’s probably the one you were reading about in the forum, is that if the smartthings cloud is not available (either because your Internet is out or because the cloud itself is down) Then the following will be true:
- you will not be able to change the armed state of smart home monitor. At all. So you can’t change it to disarmed.
That means if you have a local smart home manager automation set up so that if the armed state is “away” and the front door is open, the siren goes off, and you came home while the armed state was “away“ but your Internet was out so you were not able to change the armed state, then every time you open the front door the siren will keep going off. Because you have no way to change the automation or change the security.mode.
- you will not be able to use the app to turn the siren off because the app cannot communicate with the hub if the cloud is not available.
So these are the situations where people talk about having to get to the siren (which they might have intentionally put in a hidden position so a burglar couldn’t break it) And then take the batteries out of it.
This is just an artifact of smartthings being a cloud-based system. They didn’t have to design it this way, but they did. You can only use the app when the cloud is available. You can only change the mode when the cloud is available.
Since there is literally no way to change the armed state unless the cloud is available, the only Plan B is to use a siren which is Mains powered, not battery powered, and have previously set up a local automation which lets you manually flip a switch to cut power to the siren. ( because you can’t create a new automation if the cloud is unavailable, even if they are automations which will run locally.)
How often would you need that? Probably not very often, but often enough that you do see multiple reports of the issue in the forums.
So the problem isn’t the siren itself. The problem is not being able to change the mode from away to home if the cloud is not available and not being able to use the app if the cloud is not available.