Minnesota Boiler License Practice Exam

What is a symptom of a waterlogged expansion tank?

1. Constantly fluctuating pressure

2. Inability to heat water

3. Leakage from the tank

4. Water backing up in the system

The correct answer is: Constantly fluctuating pressure

A waterlogged expansion tank has the primary symptom of constantly fluctuating pressure. An expansion tank is designed to maintain system pressure and absorb excess water created as the water heats up and expands. When the tank is waterlogged, meaning it is filled with water instead of air, it loses its ability to accommodate this expansion. As a result, the pressure within the system can fluctuate significantly due to the lack of air cushion to absorb the changes caused by heating. In this context, while the other options may suggest issues within the boiler system, they are not direct symptoms of a waterlogged expansion tank. For instance, the inability to heat water can stem from various factors, such as faults in the heating elements or thermostat, rather than solely from the condition of the expansion tank. Leakage from the tank can indicate deteriorating seals or corrosion but does not specifically relate to being waterlogged. Similarly, water backing up in the system might suggest blockages or other malfunctions rather than a direct consequence of an expansion tank issue. Thus, fluctuating pressure is clearly the most relevant indicator of a waterlogged expansion tank.