![hvac - Can I use this unused blue wire as my C wire for my new Nest thermostat? - Home Improvement Stack Exchange hvac - Can I use this unused blue wire as my C wire for my new Nest thermostat? - Home Improvement Stack Exchange](https://i.stack.imgur.com/IpvcC.jpg)
hvac - Can I use this unused blue wire as my C wire for my new Nest thermostat? - Home Improvement Stack Exchange
![Blue "C" wire is connected to "Y" on old thermostat. New thermostat has separate "C" hookup. Where does the blue wire go - "Y" or "C"? : r/Nest Blue "C" wire is connected to "Y" on old thermostat. New thermostat has separate "C" hookup. Where does the blue wire go - "Y" or "C"? : r/Nest](https://i.imgur.com/qa9UXyW.jpg)
Blue "C" wire is connected to "Y" on old thermostat. New thermostat has separate "C" hookup. Where does the blue wire go - "Y" or "C"? : r/Nest
![My current thermostat does not a C wire connected to it but the incoming bunch has an extra blue wire that is not connected in both ends. Is it ok if I My current thermostat does not a C wire connected to it but the incoming bunch has an extra blue wire that is not connected in both ends. Is it ok if I](https://i.redd.it/16kai2jed9471.jpg)
My current thermostat does not a C wire connected to it but the incoming bunch has an extra blue wire that is not connected in both ends. Is it ok if I
![Installing Smart Thermostat: Is this blue wire a control wire, and if it's connected here does that mean it's wired at the unit? : r/hvacadvice Installing Smart Thermostat: Is this blue wire a control wire, and if it's connected here does that mean it's wired at the unit? : r/hvacadvice](https://preview.redd.it/2ee7omqpub581.jpg?auto=webp&s=a5ebbf15adc652d410c711f22f1d1a85936ec90a)
Installing Smart Thermostat: Is this blue wire a control wire, and if it's connected here does that mean it's wired at the unit? : r/hvacadvice
![wiring - Can I just extend this blue wire in furnace for Nest thermostat? - Home Improvement Stack Exchange wiring - Can I just extend this blue wire in furnace for Nest thermostat? - Home Improvement Stack Exchange](https://i.stack.imgur.com/6my9i.jpg)