New York Low Pressure Boiler Certificate of Fitness (COF) 2025 – 400 Free Practice Questions to Pass the Exam

When a defective oil cut-off valve causes after-drip, it means that fuel oil continues to drip into the combustion chamber after the burner has been turned off. This dribbling can lead to unburned fuel accumulating, which contributes to a noisy start-up and shut-down process.

At startup, the excess fuel can create an unstable ignition situation, causing irregular combustion and producing noise. Similarly, during shut down, the continued drip can result in explosive combustion events or longer ignition times, further contributing to a noisy operation. This can also lead to issues such as sooting, inefficient combustion, and potential damage to the boiler system over time due to the improper functioning of the burner.

In contrast, smooth operation, reduced emissions, and increased efficiency are typically associated with properly functioning systems. A defective cut-off valve would not promote these positive outcomes; instead, it creates conditions that lead to operational inefficiencies and noise.