I live in a condo and the heat is supplied by a gas furnace located in the building. Heat is included in my condo fee but I'm wondering if turning on the thermostat uses any electricity and how much?
Most thermostats use very little power, if any. Many of the Honeywell programmable thermostats you can buy from retail places, for instance, take 2 AA batteries for their power source and do NOT pull power from the fan unit. If your unit is a WiFi one, that may not be as true.
Either way, I'd be surprised to see one consume more than a dollar a month at most.