What is a common symptom of a blocked oil filter?

A drop in fuel pressure and system performance is indeed a common symptom of a blocked oil filter. The oil filter’s primary function is to remove impurities from the fuel before it reaches the burner. When the filter becomes clogged, it restricts the flow of oil, leading to inadequate pressure in the system. This drop in pressure can result in the burner not receiving enough fuel to operate effectively, causing a decline in overall system performance. Consequently, the heating efficiency may decrease, potentially leading to issues such as incomplete combustion or difficulty starting the burner.

In the context of the other options, a strong odor of oil may indicate a different issue, such as a leak or inadequate combustion, rather than directly correlating with a blocked filter. Increased noise from the burner could suggest issues related to combustion or mechanical wear, but it is not specifically indicative of a blocked oil filter. Frequent short cycling of the system can be related to a variety of factors, including thermostat issues or system oversizing, rather than directly pointing to the condition of the oil filter. Thus, the identification of a drop in fuel pressure and poor system performance as a symptom of a blocked oil filter is crucial in troubleshooting and maintaining oil heating systems.