What is the primary objective of a pressure switch in a gas furnace?

The primary objective of a pressure switch in a gas furnace is to ensure safe operation during ignition. This device plays a crucial role in monitoring the pressure within the furnace system, which is essential for safe combustion of gas.

When the furnace is operating, the pressure switch confirms that there is adequate airflow through the combustion chamber. It activates when it detects the necessary air pressure, signaling that it is safe to ignite the gas. If the pressure is insufficient, indicating potential issues such as a blocked vent or improper airflow, the switch prevents the ignition sequence from occurring. This safety feature helps avoid dangerous situations, such as backdrafting or gas accumulation, which could lead to explosions or carbon monoxide intrusion.

While controlling airflow, monitoring gas levels, and adjusting temperature settings are important functions within a furnace system, these tasks do not directly relate to the primary safety function that the pressure switch provides during the ignition process.