![Advice on how to wire a 4 wire RGWY wifi thermostat to an old hvac with no c wire? - Home Improvement Stack Exchange Advice on how to wire a 4 wire RGWY wifi thermostat to an old hvac with no c wire? - Home Improvement Stack Exchange](https://i.stack.imgur.com/j5dG1.jpg)
Advice on how to wire a 4 wire RGWY wifi thermostat to an old hvac with no c wire? - Home Improvement Stack Exchange
![Old thermostat works, but I can't get the Honeywell T9 to work. T9 require C Wire that was not in the wall. I added C wire & RC wire via plug-in 120v Old thermostat works, but I can't get the Honeywell T9 to work. T9 require C Wire that was not in the wall. I added C wire & RC wire via plug-in 120v](https://i.redd.it/qgn9tccrp6a91.jpg)
Old thermostat works, but I can't get the Honeywell T9 to work. T9 require C Wire that was not in the wall. I added C wire & RC wire via plug-in 120v
![Emerson Sensi 7-day Programmable Wi-Fi Smart Thermostat, No C-Wire Required for Most Systems ST55 - The Home Depot Emerson Sensi 7-day Programmable Wi-Fi Smart Thermostat, No C-Wire Required for Most Systems ST55 - The Home Depot](https://images.thdstatic.com/productImages/27c4905e-cdfc-48c6-9efd-8b1077091e04/svn/white-emerson-programmable-thermostats-st55-66_600.jpg)
Emerson Sensi 7-day Programmable Wi-Fi Smart Thermostat, No C-Wire Required for Most Systems ST55 - The Home Depot
![Programmable Wifi Smart Thermostat New For Home, No C-Wire Required By C- Wire Adapter, With Zone Remote Sensor, 24VAC - AliExpress Programmable Wifi Smart Thermostat New For Home, No C-Wire Required By C- Wire Adapter, With Zone Remote Sensor, 24VAC - AliExpress](https://ae01.alicdn.com/kf/S9aa564b35cd043f999d5cd9efa264074o.jpg_640x640Q90.jpg_.webp)
Programmable Wifi Smart Thermostat New For Home, No C-Wire Required By C- Wire Adapter, With Zone Remote Sensor, 24VAC - AliExpress
![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.jpg)
Honeywell Home C-Wire Adapter for Honeywell home Wi-Fi Thermostats and RedLINK® 8000 Series thermostats THP9045A1098 - Amazon.com
![electrical - Where should I connect the C wire in a Janitrol furnace? - Home Improvement Stack Exchange electrical - Where should I connect the C wire in a Janitrol furnace? - Home Improvement Stack Exchange](https://i.stack.imgur.com/pEsK8.jpg)
electrical - Where should I connect the C wire in a Janitrol furnace? - Home Improvement Stack Exchange
![$22/mo - Finance MoesGo Programmable WiFi Smart Thermostat for Home, No C- Wire Required by C-Wire Adapter, with Zone Remote Sensor, Remote Control Tuya/Smart Life, Compatible with Alexa and Google Assistant, 24VAC $22/mo - Finance MoesGo Programmable WiFi Smart Thermostat for Home, No C- Wire Required by C-Wire Adapter, with Zone Remote Sensor, Remote Control Tuya/Smart Life, Compatible with Alexa and Google Assistant, 24VAC](https://m.media-amazon.com/images/I/61k3DaUTqbL._AC_US1400_.jpg)