Which of the following is NOT a possible reason a pump won't pump?

The correct answer identifies that a clogged filter is not a reason for a pump to fail in its function to pump fluid. While a clogged filter can create issues in the system—such as increased pressure drop, reduced flow rates, and potential strain on the pump—it does not directly inhibit the action of the pump itself from performing its primary role. In many cases, the pump might still be able to draw water through the system, though with less efficiency or increased workload due to the restriction.

On the other hand, air leaks in the suction line can cause cavitation, disrupting the ability of the pump to maintain the necessary suction pressure, which hampers its pumping capability. Similarly, loose connections can lead to similar suction issues, allowing air to enter the system and causing the pump to lose prime. Discharge heated too high may raise the temperature of the pumped fluid beyond the pump's design specifications, potentially damaging the pump or causing it to operate inefficiently. These conditions directly affect the functionality of the pump and contribute to its inability to pump effectively.