Ignite Success: Ace the 2026 Massachusetts 2nd Class Fireman Practice Exam Today!

Ensuring that the furnace is purged before the gas pilot ignites is a crucial safety step. Purging is the process of expelling any residual or unburned gas from the system to prevent the risk of an explosion or fire due to gas accumulation in the combustion chamber or flue. It allows fresh air to enter and helps ensure that only the correct air-to-fuel mixture is present for combustion.

By effectively purging the system, the likelihood of incomplete combustion and the release of harmful byproducts is significantly reduced. This step protects both the integrity of the heating system and the safety of personnel in the surrounding area.

In contrast, while checking the low-water cutoff, gas pressure, and oil pressure are important for the overall safe functioning of the heating system, these measures do not directly address the immediate concern of ensuring that volatile gases are adequately cleared from the furnace prior to ignition.