![Trying to replace this old 2 wire thermostat for a newer digital one. Problem is older unit does not have leads labeled or which cable is which. Any help on how to Trying to replace this old 2 wire thermostat for a newer digital one. Problem is older unit does not have leads labeled or which cable is which. Any help on how to](https://i.redd.it/j9mnonzn7nu91.jpg)
Trying to replace this old 2 wire thermostat for a newer digital one. Problem is older unit does not have leads labeled or which cable is which. Any help on how to
![Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot](https://images.thdstatic.com/productImages/368f3dd6-d1b1-4460-9fce-99d5f232b5a3/svn/wasserstein-home-safety-accessories-24vadapter25ftwhtusa-44_600.jpg)
Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot
![My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee? My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee?](https://storage.googleapis.com/article_attachments/227874667/gasvalvefaststat.png)
My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee?
![My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee? My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee?](https://storage.googleapis.com/article_attachments/227874667/rwc.png)
My heat-only system only has two or three wires connected to the thermostat. Am I compatible with ecobee?
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Honeywell THX9421R5021WW 2 Wire IAQ High Definition Touch Screen Thermostat with Red LINK Technology, White: Amazon.com: Tools & Home Improvement
![Where can I connect c wire from adaptor if I don't have c terminal in my boiler control board - Home Improvement Stack Exchange Where can I connect c wire from adaptor if I don't have c terminal in my boiler control board - Home Improvement Stack Exchange](https://i.stack.imgur.com/SQO04.jpg)
Where can I connect c wire from adaptor if I don't have c terminal in my boiler control board - Home Improvement Stack Exchange
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Recently installed Amazon smart thermostat only has the option for heat. Are my wires connected correctly? : r/hvacadvice
![Can I install a nest thermostat on a 2-wire boiler (with unmarked wires)? - Home Improvement Stack Exchange Can I install a nest thermostat on a 2-wire boiler (with unmarked wires)? - Home Improvement Stack Exchange](https://i.stack.imgur.com/ZuklR.jpg)
Can I install a nest thermostat on a 2-wire boiler (with unmarked wires)? - Home Improvement Stack Exchange
![Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot](https://images.thdstatic.com/productImages/daa16bb7-48c2-4420-b03c-73cc52ea5d82/svn/wasserstein-home-safety-accessories-24vadapter25ftwhtusa-64_600.jpg)
Wasserstein 24-Volt Transformer and C-Wire Adapter for Google Nest Thermostat, Learning Thermostat, Thermostat E and Wyze Thermostat 24VAdapter25ftWhtUSA - The Home Depot
![2-Wire heat only furnace for Nest E. The Nest is having problems staying powered. Can I use an external 24V power supply? How would I route the additional wires? https://www.amazon.com/dp/B07FT2RCG9/ref=tsm_1_tp_tc : r/ Nest 2-Wire heat only furnace for Nest E. The Nest is having problems staying powered. Can I use an external 24V power supply? How would I route the additional wires? https://www.amazon.com/dp/B07FT2RCG9/ref=tsm_1_tp_tc : r/ Nest](https://i.redd.it/sh6zbm6409h61.jpg)