Proper state to set rest or template sensor to unknown

Configuration
1

What is the recommended way to set a binary_sensor or a sensor to an unknown state?

"Unknown"
"unknown"
"None"
"none"
""
"null"
...
2

The second one.

1 Like
3

Does not seem to work when unit_of_measurement suggests a numeric value:

ValueError: Sensor sensor.minuten_bis_regen has device class 'None', state class 'measurement' unit 'min' and suggested precision 'None' thus indicating it has a numeric value; however, it has the non-numeric value: 'unknown' (<class 'str'>)

4

And that is the danger of reading 3 year old posts. Home Assistant has changed. Ask in a new topic with your sensor config.

5

So what is the recommended way now?