The thermostat pcb is a bit more general than the name suggests: basically, it's a shield for turning any device on and off depending on the reading of one or two sensors, according to rules programmed in Arduino code.

It requires 120/240 V AC power and a load current of less than 10 A. The max load current can be increased to 15 A by swapping in a slightly more expensive relay. A built-in AC-DC converter (again, 120/240 V) powers the Arduino and shield with up to 1 W (more than enough for most Arduino applications).

The user is responsible for cutting a power cord and connecting it to the correct screw terminals; color-coding and text labels make this safe and straightforward.

The shield is intended to work with thermistors connected to screw terminals. However, any passive analog sensor compatible with the Arduino's ADC can also be connected to the screw terminal, and a powered analog sensor can also be used by soldering the 5V lead to the board.

Schematic symbols are all stored in thermostat.lib. Component footprints are all stored in thermostat.pretty/. There should be no library issues.