Which component is typically responsible for the ignition process in gas furnaces?

The ignition control module is fundamentally responsible for the ignition process in gas furnaces. This component initiates the sequence necessary for igniting the gas supplied to the burners. Upon receiving a signal, the ignition control module activates the igniter, which can be either a hot surface igniter or a spark igniter, depending on the furnace design.

Once the igniter is energized, it generates the necessary heat or spark to ignite the gas flowing into the combustion chamber. This process is critical for the furnace to produce heat effectively. The ignition control module also monitors the operation to ensure safety, shutting down the system in the event of a failure to ignite.

In contrast, while the flame sensor detects the presence of the flame to ensure safe operation, it does not initiate the ignition process. The thermostat acts as a control device that regulates temperature but does not directly engage with the ignition. The blower fan is responsible for circulating heated air throughout the home but has no role in the ignition of the gas.