If you are buying wire for a (like Nest or Ecobee), do not settle for anything less than a 5-conductor cable. Learn about the common or C wire - Google Nest Help
Standard for most modern heat/AC systems. It includes the crucial C-wire . 8-Wire: Recommended for heat pumps or multi-stage systems. 2. The "C-Wire" Factor buy thermostat wire
This is the number of conductors (individual wires) inside the cable. 2-Wire: Heating only (older boilers). If you are buying wire for a (like
This is the gauge (AWG) . Most residential systems use 18-gauge solid core wire . Avoid using thinner wires (like 24 AWG) for long runs, as they can cause signal loss. as they can cause signal loss.