The Additional Valves (https://shop.netatmo.com/eur_en/group-3nav-eu.html)
only work with an Thermostat or starter pack with bridge.
See https://netatmostatic.blob.core.windows.net/static/energy_helpchoice/helpchoice_EN.pdf
The Homey App just connects to the Cloud Services API.
Pessence/Welcome, Weather station, and Smart Indoor Air Quality Monitor are complete independent products each connecting with their own base station too your Wifi.
