![Amazon.com: C Wire Accessory Common Wire Kit for Most 24 VAC Thermostats (4 to 5 Wires), White (1 Pack) : Tools & Home Improvement Amazon.com: C Wire Accessory Common Wire Kit for Most 24 VAC Thermostats (4 to 5 Wires), White (1 Pack) : Tools & Home Improvement](https://m.media-amazon.com/images/I/71XSABB637L.jpg)
Amazon.com: C Wire Accessory Common Wire Kit for Most 24 VAC Thermostats (4 to 5 Wires), White (1 Pack) : Tools & Home Improvement
![Honeywell Home C-Wire Adapter for Honeywell home Wi-Fi Thermostats and RedLINK® 8000 Series thermostats THP9045A1098 - Amazon.com Honeywell Home C-Wire Adapter for Honeywell home Wi-Fi Thermostats and RedLINK® 8000 Series thermostats THP9045A1098 - Amazon.com](https://m.media-amazon.com/images/I/71AjSMTbLJL._AC_UF350,350_QL80_.jpg)
Honeywell Home C-Wire Adapter for Honeywell home Wi-Fi Thermostats and RedLINK® 8000 Series thermostats THP9045A1098 - Amazon.com
![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)