The Trvs are sonoff devices. Some will be using their own thermostat but some I’ll have a separate room thermostat.
Try something like this:
{{ state_attr('climate.TRV1', 'hvac_action') == 'heating' or state_attr('climate.TRV2', 'hvac_action') == 'heating' }}
This should return true if one or more of the TRVs are on.
Oh they’re all connected and controllable. I just don’t have much of an idea how to manage and was thinking there might be a blueprint or something for controlling then as a system. I’m completely new to ha.