Hi HoltsBlossoms,
You'll see E257 code if the wires in your thermostat weren't configured properly in the Home app.
To isolate: could you please share the photo of your previous and current thermostat wiring? Also, you can try updating the wires you have in the Google Home app settings.
Please check this out and let me know how it goes:
- Open the Home app.
- Touch and hold your device's tile.
- Open Settings .
- Select Thermostat.
- Tap Wiring. Here you’ll see the current configuration of your thermostat’s wires.
- Tap Update Wiring and read through the info on screen before going to the next step.
- Follow the steps in the app to update your thermostat’s wires.
- Pay special attention to any instructions regarding how to handle your system wires or turning your system power off or on.
- After you’ve updated your wiring, test your system to make sure that it's working correctly.
Best,
Jenelyn
