Thermostat Voltages, or T-Voltage for short, is a term used to refer to electrical potential differences between two points. It is typically used to indicate the levels of resistance and output from an electrical circuit when being tested or monitored. This measurement is important for testing the performance and efficiency of an electrical device in order to ensure it is functioning correctly. Measuring this voltage can also aid in troubleshooting any issues with the device. Knowing how much voltage is flowing through a circuit can tell you if something is not working properly.