What is a common cause for a dirty fuel oil strainer?

A dirty fuel oil strainer is typically attributed to a contaminated fuel supply. When fuel oil is delivered, it may include impurities such as dirt, water, rust, or other contaminants that come from various sources, including transportation, storage tanks, and piping systems. These contaminants accumulate in the strainer, leading to clogging, which obstructs the flow of fuel to the burner and can negatively affect the efficiency and operation of the heating system.

While issues like a poor filtration system, faulty burner operation, or aging boiler components can lead to operational problems, they do not directly cause the strainer itself to become dirty. A well-designed filtration system should minimize contamination, and while faulty operation or aging components may create issues in fuel delivery and burning efficiency, the immediate cause of dirt accumulation in the strainer primarily stems from the quality and cleanliness of the fuel oil being supplied.