Nest Wiring

[Ralph]

R and Rc wire used on old thermostat. New Nest only has R

[MelbaDT]

Hi Ralph, 

Thanks for reaching out to the Google Nest Community. 

If you have an Rh and an Rc wire, the Rh wire is the power wire for your heating system. Some HVAC systems, called dual transformer systems, use separate power sources for heating and cooling (Rc and Rh). Since you have both an Rh and an Rc wire, you have a dual transformer system and it is strongly recommended that you contact a local pro to prevent damage to your system. 

To know more about the wires on your thermostat, please refer to this guide: https://bit.ly/34shX5E

Hope this helps. 

Best, 

Melba

[MelbaDT]

Hey there, 

Checking back in — do you still need help wiring your Nest thermostat?

Best, 

Melba