Massachusetts Oil Burner License Practice Test

What might it indicate if the vacuum reading is significantly above the calculated level?

1. Normal operation

2. Leak in the system

3. Clogged oil filter

4. Fuel unit failure

The correct answer is: Clogged oil filter

A vacuum reading that is significantly above the calculated level indicates that there is an abnormal condition within the system. In this case, if the reading is too high, it suggests that the flow of oil is being restricted. When analyzing options, a clogged oil filter would indeed result in higher vacuum readings because as the filter becomes blocked, the pump must work harder to draw fuel through the filter. This creates a greater differential pressure, leading to an elevated vacuum reading. Hence, a significantly above-calculated vacuum reading is a direct indicator of a system obstruction caused by a clogged filter. In contrast, while other factors such as leaks, fuel unit failures, or even normal operation might influence vacuum readings, they would not specifically account for a consistent rise above the expected levels as a clogged filter would. Recognizing this particular condition allows for timely maintenance actions to resolve the flow restriction and restore proper function.