Hi @mkaplan2534,
This is no ‘hard’ limit constraint on the number of ecobee thermostats that My Ecobee Init (Service Manager) can manage…
However, it is recommended to not select more than 3 ecobee3 therrmostats per instance of my Service Manager in order to avoid the ST platform rate limiting issue as specified here:
especially, if you have many remote sensors and you want to expose them thru my ecobee3RemoteSensorInit smartapp.
If you do have more than 3 ecobee thermostats, you just need to create another instance of MyEcboeeInit by specifying a different name at the last page (Notifications and other settiings) when prompted (see following parameter below)
section([mobileOnly:true]) {
label title: "Assign a name for this SmartApp", required: false
}
Regards.