Which action helps prevent pump overheating when using tank supply with intermittently used attack lines?

• A. High idle
• B. Set circulator valve to tank position
• C. Fully open auxiliary cooling valve
• D. Overheating is not a problem

Answer: (B)

The main idea is keeping the pump cooled when the attack lines aren’t continuously in use. When you’re using a tank supply and the attack lines are used intermittently, water can sit in the pump and overheat as there’s little or no flow through the discharge side. Setting the circulator valve to the tank position directs water from the tank through the pump and back, circulating it continuously to provide cooling even when no water is being sent to the attack lines. This keeps the pump from overheating while you manage intermittent flows.

High idle can increase engine speed and cooling a bit, but it doesn’t ensure the pump itself is circulating tank water for cooling. Fully opening an auxiliary cooling valve might aid engine cooling, but it doesn’t address the need to circulate tank water through the pump for direct pump cooling during intermittent use. Overheating is a real concern in this setup, so the targeted action is to keep that tank-to-pump circulation active.