What are the two standard gauges for commonly used thermostat wire?

The two standard gauges for commonly used thermostat wire are 18 and 20 AWG. These gauges are typically used in low-voltage applications, such as thermostats and control circuits, making them suitable for the majority of residential and commercial heating and cooling systems.

The 18 AWG wire is often preferred due to its balance between wire resistance and ease of handling, allowing for efficient signal transmission without significant voltage drop. Meanwhile, 20 AWG wire, being slightly smaller, can also be used in situations where the distance is shorter or the load is minimal.

Understanding the appropriate wire gauge is crucial for ensuring proper operation of thermostats and connected components, as using the wrong gauge could lead to issues such as overheating or signal loss, potentially compromising system performance and safety.