![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
![Is the blue wire on my thermostat the proper “C” wire required to upgrade to a smart thermostat? Thanks! : r/hvacadvice Is the blue wire on my thermostat the proper “C” wire required to upgrade to a smart thermostat? Thanks! : r/hvacadvice](https://i.redd.it/koef096o7cn91.jpg)
Is the blue wire on my thermostat the proper “C” wire required to upgrade to a smart thermostat? Thanks! : r/hvacadvice
![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
![electrical - Installing of Honeywell Wi-Fi Programmable Thermostat - Home Improvement Stack Exchange electrical - Installing of Honeywell Wi-Fi Programmable Thermostat - Home Improvement Stack Exchange](https://i.stack.imgur.com/OrEg6.jpg)
electrical - Installing of Honeywell Wi-Fi Programmable Thermostat - Home Improvement Stack Exchange
![Need help wiring nest thermostat, black and dark blue wires are loops. I have a heat pump. : r/thermostats Need help wiring nest thermostat, black and dark blue wires are loops. I have a heat pump. : r/thermostats](https://i.redd.it/9eij8wtnze081.jpg)
Need help wiring nest thermostat, black and dark blue wires are loops. I have a heat pump. : r/thermostats
![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
![New thermostat wiring help bought new Honeywell t10 and want to wire it properly the old thermostat had jump from w2 to y2 and jumper from r and rc and a blue New thermostat wiring help bought new Honeywell t10 and want to wire it properly the old thermostat had jump from w2 to y2 and jumper from r and rc and a blue](https://i.redd.it/0p3x4p6dapa81.jpg)
New thermostat wiring help bought new Honeywell t10 and want to wire it properly the old thermostat had jump from w2 to y2 and jumper from r and rc and a blue
![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
![Honeywell Thermostat Instructions, Wire Terminals, Functions, Color Code! Furnace and AC! Heat Pump! - YouTube Honeywell Thermostat Instructions, Wire Terminals, Functions, Color Code! Furnace and AC! Heat Pump! - YouTube](https://i.ytimg.com/vi/PqZd6YeLQ_A/maxresdefault.jpg)
Honeywell Thermostat Instructions, Wire Terminals, Functions, Color Code! Furnace and AC! Heat Pump! - YouTube
![Understanding and Wiring Heat Pump Thermostats with AUX & Em. Heat! Terminals, Colors, Functions! - YouTube Understanding and Wiring Heat Pump Thermostats with AUX & Em. Heat! Terminals, Colors, Functions! - YouTube](https://i.ytimg.com/vi/qiAOvJhq8_s/maxresdefault.jpg)