Ok, what is *hysteresis*?

[Trying_to_learn]

Thanks.

I think what really threw me was the original person who was asking in another thread.

They had the values back to front with the upper and lower limits.

So rather than having:

22 18

They had 18 22.

And when I went into the thread and did what they were doing, I just dug myself into a big hole.

[Brian5600]

Your fridge and freezer works this way too. Cool down to a setpoint and then warm up to a higher setpoint, before starting over.
In this case I also think it is only the first message that goes by, when You hit a thresshold. Like a switch turn on/off, it is an indikator to change state on/off, it just user the message for this purpose.
The node might bee better with a validation of input “Rising treshold” > “Falling treshold”.

[Trying_to_learn]

Yes, but as I explained, the person I was trying to help had the numbers the wrong way around and I didn't click on that problem.