Temperature "stall" notification

Configuration
1

Hello

I have an idea but I don’t know how to achieve it. I’ll describe the situation.

I have a wood burning sauna and I’ll have to fill the heater with wood twice for the temperature to get to the level I want. That means that I have to periodically go and check if the first batch of wood is burnt out and I could fill it again. Often it’s not and I’ll have to make multiple trips for that. That is what I want to change.

My idea is that I install a Shelly UNI, with temperature sensor (I already have those) into the sauna and measure the temperature. What I can’t figure out is the following: When starting the burn, the temperature will increase exponentially. When the first batch of wood is starting to burn out, the rise of the temperature will level out and even starting to lower. What I want is that I get an notification when the temperature is for example more than 40 degrees C ( first batch of wood usually gets me to more than 40 degrees) and haven’t risen (or even lowered) about 5 minutes. That means the wood is burnt out enough for me to go and fill the heater it up again. And I want it to happen only once, since when the temperature reaches the goal, it starts to fluxuate anyway, since people open the door and filling/burning out the heater while people go in sauna is not the issue anymore.

Any ideas?

2

you can use a derivative sensor that will give you a rate of change of the temperature. you can use that as being either very small or negative to trigger an automation.

be aware that the derivative sensor will never read 0 (it’s either a bug or a feature depending on who you ask).

3

Thanks for the answer. But could You be more specific?

4

Search your helpers for derivative. It will create an entity that will show you the rate of change on your entity.

5

The groundwork to fix this was added many versions ago, just waiting on someone to update the integration :wink:

You’ll noticed the issue was fixed for the integration integration.

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