If you are pumping from a draft and the strainer is becoming blocked, you will be able to recognize it when the:

• A. Vacuum gauge shows increased negative pressure
• B. Flow meter shows increased flow
• C. Pressure gauge rises
• D. Temperature gauge rises

Answer: (A)

When pumping from a draft, the pump pulls water through the intake and creates suction at the inlet. If the strainer becomes blocked, the path for water is restricted, so the pump must generate greater suction to draw water through. That shows up as a more negative reading on the vacuum gauge, indicating increased suction at the inlet. The flow would typically decrease, and a discharge pressure reading wouldn’t rise due to a blockage; the temperature might increase only if the motor is overloaded for other reasons, not as a direct cue of a clogged intake. Thus, a noticeable rise in vacuum (more negative pressure) is the clear sign.