![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
![furnace - Connected C-Wire (previously unused) to thermostat, but still no power? - Home Improvement Stack Exchange furnace - Connected C-Wire (previously unused) to thermostat, but still no power? - Home Improvement Stack Exchange](https://i.stack.imgur.com/zx9IU.jpg)
furnace - Connected C-Wire (previously unused) to thermostat, but still no power? - 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)