![Maxdot 24V 40VA Thermostat and Doorbell Transformer, Power Supply Compatible with Nest, Ecobee, Sensi and Honeywell Maxdot 24V 40VA Thermostat and Doorbell Transformer, Power Supply Compatible with Nest, Ecobee, Sensi and Honeywell](https://c.shld.net/rpx/i/s/pi/mp/27954/prod_15248436517?src=https%3A%2F%2Fimages-na.ssl-images-amazon.com%2Fimages%2FI%2F519YAD%2BuCML.jpg&d=1189fee0673565a346bcf96f3c860bdfe28e041f&hei=450&wid=450)
Maxdot 24V 40VA Thermostat and Doorbell Transformer, Power Supply Compatible with Nest, Ecobee, Sensi and Honeywell
![Newbie: Any way to add a c wire to existing transformer or wires? Do I need a new transformer with a “c” terminal? (Trying to connect a Wi-Fi thermostat to control boiler) : Newbie: Any way to add a c wire to existing transformer or wires? Do I need a new transformer with a “c” terminal? (Trying to connect a Wi-Fi thermostat to control boiler) :](https://preview.redd.it/rx53me8zs8z71.jpg?width=640&crop=smart&auto=webp&s=ac89cd0dbc4fb66351ef8e71110a553c069509a4)
Newbie: Any way to add a c wire to existing transformer or wires? Do I need a new transformer with a “c” terminal? (Trying to connect a Wi-Fi thermostat to control boiler) :
![24 Volt Transformer, C Wire Adapter Thermostat, Compatible with Smart Thermostats and Doorbells Power Supply (23ft Cable) - Amazon.com 24 Volt Transformer, C Wire Adapter Thermostat, Compatible with Smart Thermostats and Doorbells Power Supply (23ft Cable) - Amazon.com](https://m.media-amazon.com/images/I/71g-TO6zv7L._AC_UF1000,1000_QL80_.jpg)
24 Volt Transformer, C Wire Adapter Thermostat, Compatible with Smart Thermostats and Doorbells Power Supply (23ft Cable) - Amazon.com
![HQRP Transformer Primary 120V-240V, Secondary 24V Compatible with HVAC Furnace, Nest Ecobee Sensi Honeywell Thermostat, Nest Doorbell 120v-240v-to-24v Replacement 40VA Power Supply C(UR) US Certified - Walmart.com HQRP Transformer Primary 120V-240V, Secondary 24V Compatible with HVAC Furnace, Nest Ecobee Sensi Honeywell Thermostat, Nest Doorbell 120v-240v-to-24v Replacement 40VA Power Supply C(UR) US Certified - Walmart.com](https://i5.walmartimages.com/asr/01d70c24-f83d-4b82-9b0c-70e227d34b58.ef7799de0ec9e4687111745b548d9ed7.jpeg?odnHeight=768&odnWidth=768&odnBg=FFFFFF)
HQRP Transformer Primary 120V-240V, Secondary 24V Compatible with HVAC Furnace, Nest Ecobee Sensi Honeywell Thermostat, Nest Doorbell 120v-240v-to-24v Replacement 40VA Power Supply C(UR) US Certified - Walmart.com
![Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com](https://i5.walmartimages.com/asr/8905e227-9b5f-4590-a5ed-bf6f2082324f.1b372af223b4d0cbfb67863fb4d4e1a8.jpeg?odnHeight=768&odnWidth=768&odnBg=FFFFFF)
Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com
![DEWENWILS 24VAC 40VA Transformer, Plug in with PTC Fuse, Compatible with Nest, Ecobee, Sensi and Honeywell Ring Video Doorbell, Thermostat, 3 Prong - Yahoo Shopping DEWENWILS 24VAC 40VA Transformer, Plug in with PTC Fuse, Compatible with Nest, Ecobee, Sensi and Honeywell Ring Video Doorbell, Thermostat, 3 Prong - Yahoo Shopping](https://s.yimg.com/lo/api/res/1.2/4SS4oodYU.QP7jn4U6kSyA--/YXBwaWQ9ZWNfaG9yaXpvbnRhbDtoPTQwMDtzcz0xO3c9NDAw/https://m.media-amazon.com/images/I/41gCaL6ovAL._SL500_.jpg)
DEWENWILS 24VAC 40VA Transformer, Plug in with PTC Fuse, Compatible with Nest, Ecobee, Sensi and Honeywell Ring Video Doorbell, Thermostat, 3 Prong - Yahoo Shopping
![I have two separate R wires on my thermostat. What do I need to know about my ecobee thermostat installation? I have two separate R wires on my thermostat. What do I need to know about my ecobee thermostat installation?](https://storage.googleapis.com/article_attachments/Dual%20transformer_Backplate_Dual%20transformer%20separate%20R%20wires.png)
I have two separate R wires on my thermostat. What do I need to know about my ecobee thermostat installation?
![wiring - How to add Thermostat C Wire to Furnace TH/TR and Transformer - Home Improvement Stack Exchange wiring - How to add Thermostat C Wire to Furnace TH/TR and Transformer - Home Improvement Stack Exchange](https://i.stack.imgur.com/GNpOf.jpg)
wiring - How to add Thermostat C Wire to Furnace TH/TR and Transformer - Home Improvement Stack Exchange
![24V 40VA Thermostat and Doorbell Transformer, Power Transformer Compatible with Nest, Honeywell, Ecobee and Sensi Thermostat, Nest Hello and All Versions of Doorbells - Amazon.com 24V 40VA Thermostat and Doorbell Transformer, Power Transformer Compatible with Nest, Honeywell, Ecobee and Sensi Thermostat, Nest Hello and All Versions of Doorbells - Amazon.com](https://m.media-amazon.com/images/I/71EybWNIWML._AC_UF1000,1000_QL80_.jpg)
24V 40VA Thermostat and Doorbell Transformer, Power Transformer Compatible with Nest, Honeywell, Ecobee and Sensi Thermostat, Nest Hello and All Versions of Doorbells - Amazon.com
![Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com](https://i5.walmartimages.com/seo/Bensn-24-Volt-Transformer-C-Wire-Adapter-Thermostat-All-Versions-Doorbell-Nest-Ecobee-Sensi-Honeywell-315-Inch-Cable-24V-Transformer_c0e2d4f8-4bb9-413b-8699-729efd2902bd.0ee205a533024603e8700ea7b41146ef.jpeg)
Bensn 24 Volt Transformer, C Wire Adapter Thermostat with All Versions of Doorbell and Thermostat for Nest, Ecobee, Sensi and Honeywell, 315 Inch Cable 24V Transformer - Walmart.com
![Honeywell Home 24 Volt Transformer Selectable-flexible Programmable Thermostat in the Programmable Thermostats department at Lowes.com Honeywell Home 24 Volt Transformer Selectable-flexible Programmable Thermostat in the Programmable Thermostats department at Lowes.com](https://mobileimages.lowes.com/productimages/fafa1dda-e185-4abe-9e54-9968fd7d6448/64668906.jpg?size=pdhism)
Honeywell Home 24 Volt Transformer Selectable-flexible Programmable Thermostat in the Programmable Thermostats department at Lowes.com
![24 Volt Transformer, C Wire Adapter Thermostat, Competible with All Versions of Ring Doorbell Thermostat for Nest Ecobee, Sensi 24 Volt Transformer, C Wire Adapter Thermostat, Competible with All Versions of Ring Doorbell Thermostat for Nest Ecobee, Sensi](https://ae01.alicdn.com/kf/Sfddeed93340c410e842515a3e4e69eb2E/24-Volt-Transformer-C-Wire-Adapter-Thermostat-Competible-with-All-Versions-of-Ring-Doorbell-Thermostat-for.jpg)
24 Volt Transformer, C Wire Adapter Thermostat, Competible with All Versions of Ring Doorbell Thermostat for Nest Ecobee, Sensi
![Xwartre UL Certified Thermostat C Wire 24V Transformer, White Adapter Compatible with Honeywell, Nest, Emerson, Ecobee, Wyze Thermostat and Most Doorbells (26FT Power Cable) - Amazon.com Xwartre UL Certified Thermostat C Wire 24V Transformer, White Adapter Compatible with Honeywell, Nest, Emerson, Ecobee, Wyze Thermostat and Most Doorbells (26FT Power Cable) - Amazon.com](https://m.media-amazon.com/images/I/51EPruGRJwL._AC_UF1000,1000_QL80_.jpg)