https://www.googlenestcommunity.com/t5/Nest-Thermostats/Existing-system-has-two-C-wires/m-p/557210#M111340 <P>Hi&nbsp;<A href="https://goo.gle/3Gynze4" target="_blank">Iwan22</A>,</P> <P>&nbsp;</P> <P>Thanks for checking it with us. I'd like to know more about it. A few questions: in what country are you located? What is the make and model of your system? Could you please take a photo of the wires connected to your system's control board? Ensure that the labels of the wires are visible.&nbsp;</P> <P>&nbsp;</P> <P>Best,</P> <P>Jenelyn</P> Thu, 07 Dec 2023 16:37:48 GMT Jenelyn_O 2023-12-07T16:37:48Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Existing-system-has-two-C-wires/m-p/555185#M110910 <P>My existing system has two C wires hooked up, what do I use for my new nest learning thermostat? Both? Pick one?</P><P><BR />Existing system has these wires connected: C, C, Rc, Y, W, G</P><P>thanks</P> Sun, 03 Dec 2023 22:14:22 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Existing-system-has-two-C-wires/m-p/555185#M110910 Iwan22 2023-12-03T22:14:22Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Existing-system-has-two-C-wires/m-p/557210#M111340 <P>Hi&nbsp;<A href="https://goo.gle/3Gynze4" target="_blank">Iwan22</A>,</P> <P>&nbsp;</P> <P>Thanks for checking it with us. I'd like to know more about it. A few questions: in what country are you located? What is the make and model of your system? Could you please take a photo of the wires connected to your system's control board? Ensure that the labels of the wires are visible.&nbsp;</P> <P>&nbsp;</P> <P>Best,</P> <P>Jenelyn</P> Thu, 07 Dec 2023 16:37:48 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Existing-system-has-two-C-wires/m-p/557210#M111340 Jenelyn_O 2023-12-07T16:37:48Z