No power. Check your wiring and system power. You didn't fry it.
First, confirm your HVAC system master switch or circuit breaker is ON. Turn your heat or AC on at the thermostat. Wait. Feel for air at the vents.
If no power:
- Power off the HVAC system at the breaker.
- Remove the thermostat from the wall to inspect the backplate wiring.
- You have one of three scenarios. Identify yours:
- With a C-wire: You don't need the PEK adapter. Ensure the blue or black C-wire is securely in the C terminal.
- Without a C-wire: You must use the supplied Power Extender Kit (PEK). The PEK terminal is labelled PEK+ on the Premium model. Follow the PEK wiring diagram exactly.
- With multiple G wires: This requires a specific wiring setup. Use the ecobee app for step-by-step videos customized to your wiring.
Heads up: Always label wires before disconnecting your old thermostat. If you have a jumper between Rc and Rh, leave it alone. Only label wires from the wall.