Something will fail to render in a future update

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?

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

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.

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