![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
![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
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Southwire 64169622 5 Conductor 18/5 Thermostat Wire; 18-Gauge Solid Copper Class 2 Power-Limited Circuit Cable; 50-Feet; Brown - Electrical Wires - Amazon.com
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