Turn on netatmo thermostat relay with an other netatmo thermostaat

hello,

I have 2 smart Netatmo Thermostats. with the corresponding relays.

The first thermostat is in the bedroom, with underfloor heating and the 2nd thermostat is in the living room which turns on the central heating boiler.

I would like that if the first thermostat gets above the set temperature the relay of the second thermostat turns on. so that if the floor heating turns on that the cv also turns on so that the floor heating actually does pump hot water around?

Does anyone know the best way to make this automation?

Start with your trigger:

That would be a numeric state trigger.

Then move on to your action:

That would likely be the switch turn on service. Or maybe climate turn on.