Something will fail to render in a future update

[jatgm1]

states(‘input_number.main_room_low_temp’)|float -
states(‘input_number.main_room_temp_deviation_hot’)|float }}’ but no default was specified. Currently ‘float’ will return ‘0’, however this template will fail to render in Home Assistant core 2022.1

Is the message I get. Does this mean I need to like add zero to the automation that this is in? I think it’s a template. And if that the | thing and then a zero?

[AdmiralStipe]

Updating Templates with the new default values in 2021.10.x

I keep seeing the same question about the new default argument for the templating. This post will cover all possible ways to define default. All the methods that were changed: acos as_timestamp asin atan atan2 cos float log round sin sqrt strptime tan timestamp_custom timestamp_local timestamp_utc Each of them have the exact same default functionality but a different number of arguments. There are multiple ways to use these functions, and this is where all the confusion lies. Understandi…

[jatgm1]

That a lot of information, much of which I do not understand. Am I supposed to just put | 0 after the float now?

[AdmiralStipe]

For your case it should be
{{ states(‘input_number.main_room_low_temp’) | float(0) - states(‘input_number.main_room_temp_deviation_hot’) | float(0) }}

So, in case any of input numbers fails, it will be replaced with zero. Of course you can put in any number instaed of zero, if you prefer.

[jatgm1]

Oh ok. Out of curiosity why Remove the automatically defaulting to zero thing? Security flaw or something?