24 Volt Transformer, C Wire Adapter Thermostats, Compatible with Ecobee, Nest and Honeywell Smart WiFi Thermostat, Ring Nest Hello Skybell August Doorbell (White) : Amazon.ca: Tools & Home Improvement
My ecobee thermostat won't turn on. How can I troubleshoot?
Installing your ecobee thermostat with the Power Extender Kit (no C wire)
I have two separate R wires on my thermostat. What do I need to know about my ecobee thermostat installation?