@BatraD, the ST thermostat DTH (Device Type Handler) does not support the basic
methods to set the ecobee thermostat to Away or Home.
You’d need a DTH that supports the basic methods.
Fortunately, I’ve developed a custom DTH that does that and much more. Since V5, My ecobee device can even provide some custom tips based on your actual indoor/outdoor conditions at your home.
As you may know, I ask for a modest contribution due the amount of time required to expose all rich ecobee APIs to ST. My Ecobee device is also more resilient than the ST stock device as far as cloud-to-cloud connections between ST and ecobee.
You can find My ecobee Device at my store:
http://www.ecomatiqhomes.com/store
Regards.
P.S. Another alternative would be to use IFTTT but the change won’t be reflected immediately in the ST stock device as it’s different integration and they do not talk to each other.