Hello LeonardShepard,
It's nice to see you reaching out here in the Google Nest Community Forum about your system compatibility with the Nest Thermostat! I'd be glad to check into this for you.
Can you post a picture of your thermostat's wiring? From what country are you posting? Also, what's the make and model of your HVAC system?
I'll look forward to your response.
Regards,
Mark
