Red Seal Oil Heat System Technician Practice Exam

What are the consequences of using biodiesel in older oil heating systems?

1. Increased efficiency and reduced emissions

2. No noticeable impact on system performance

3. Compatibility issues and degradation of system components

4. Improved lubrication of the fuel pump

The correct answer is: Compatibility issues and degradation of system components

Using biodiesel in older oil heating systems can lead to compatibility issues and degradation of system components. Biodiesel is derived from renewable sources and has different chemical properties compared to traditional petroleum-based heating oil. Older systems may not be designed to accommodate the higher levels of oxygen and the different solvent properties found in biodiesel. As a result, components such as seals, gaskets, and hoses that were created with petroleum-based fuels in mind can deteriorate or swell when exposed to biodiesel. This degradation can lead to leaks, clogs, and ultimately costly repairs. Additionally, the presence of biodiesel can also promote the growth of microbial organisms in the fuel, which can further clog filters and damage the system. While there are potential benefits to using biodiesel, such as reduced emissions, the main concern in older systems is the compatibility challenge, underscoring why this option is the most relevant consequence. Newer systems are typically better equipped to handle biodiesel blends without significant issues.