Nest thermostat with only one R wire but my old thermostat have a R and RC wire connected

[Synergy]

I  have separate heating and air conditioning systems, with separate R and Rc wires that come out of the wall and are connected to my system but my nest thermostat has only one 1 R wire. How do I connect it correctly?

 thanks

[MelbaDT]

Hey Synergy, 

Thanks for posting and sorry for the delayed response.

Do you happen to have a dual transformer system which uses separate power sources for heating and cooling? If yes, it's strongly recommended that you contact a local pro to prevent damage to your system. You may also check on this link for more information. 

Best, 

Melba

[MelbaDT]

Hey there, 

Just checking back in — let me know if you still need help with your Nest thermostat. 

Best, 

Melba

[MelbaDT]

Hi, 

Since it's been since this thread was last updated, we'll be locking it if we won't hear back from you again within a day. Should that happen, feel free to create a new one should you have more questions or have other concerns in the future. 

Best, 

Melba