Minnesota Boiler License Practice Exam 2025 – All-in-One Guide to Passing with Confidence

After a hot water boiler has been drained, cleaned, and refilled with water, it is crucial to evacuate air from the system. This process is essential because air trapped in the boiler and the piping can lead to various operational issues, including reduced efficiency, noise, and potential damage to the system.

When air accumulates in the pipes, it can create air pockets that hinder water flow, leading to inadequate heating and uneven temperature distribution. By bleeding or purging the air out of the system, you ensure that water can circulate freely, allowing the boiler to operate effectively and maintain the desired heat levels efficiently. This process enhances the system’s overall performance and longevity.

In contrast, resetting aquastats, performing blowdown, or resetting the sail switch are not immediate steps taken after refilling the boiler with water. These actions may be necessary at different points in maintenance or troubleshooting, but the immediate priority following a refill is to remove any air from the system to ensure safe and efficient operation.