What is the primary purpose of a thermocouple in heating systems?

The primary purpose of a thermocouple in heating systems is to generate electrical signals. A thermocouple consists of two different types of metals joined together at one end. When the junction experiences a change in temperature, it produces a small voltage that correlates with that temperature difference, based on the thermoelectric effect. This generated voltage can be used to measure temperature and provide feedback for system controls, such as modulating burners in heating systems or ensuring safe operation by monitoring temperature limits.

Monitoring fan speed, controlling compressor operation, and discharging capacitors are functions associated with other components in HVAC systems. While these functions are vital for overall system performance, they do not pertain to the primary role of a thermocouple, which is focused specifically on temperature measurement and the resulting electrical signal generation.