Is my system compatible

[ShannaJD]

Is my system system compatible I have a Honeywell rth221b1021 I use wires O , G, Y,  W, and R 

[ciprianocoche]

Hi ShannaJD,

Thank you for reaching out to the Google Nest Community team! Based on your existing wiring, this is definitely compatible with Google Nest thermostats.

Here's how we can confirm compatibility:

1. Google offers a tool to check compatibility based on your heating and cooling system type.
2. During installation, the Google Home or Nest app will walk you through steps to confirm compatibility and provide a custom wiring guide for your specific thermostat model.

Please keep in mind that while most common wires (R, G, Y, and W) are compatible, some Google thermostats (Nest Thermostat 2020) might require a common wire (C-wire) for continuous power. The checkers mentioned above will also address this.

Let me know if you have any other questions.
 

Best Regards,

Jonathan