How to Diagnose a Simple Pump That Isn’t Pumping Water

If your Simple Pump isn’t pumping water, don’t worry. This step-by-step guide will help you identify the issue using an easy and effective method called the bag test. This tutorial walks you through each step of the process, the tools you’ll need, and tips to fix common problems.

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Tools Needed:

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• Simple Pump with check valve engage kit removed
• Thin, loose produce bag (preferably clear plastic)
• Tape (such as masking or painter’s tape)
• Basic wrench or screwdriver to remove bolts

Step 1: Prepare the Pump for the Bag Test

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To start, remove the check valve engage from your Simple Pump. This part is typically located at the pump outlet and may include a longer nipple setup for easy filling. You don’t need to remove the nipple thoroughly; just ensure you have a place to secure the bag tightly.

Tip: Keep the nipple intact so you can tape the bag around it for a secure fit.

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Step 2: Attach the Produce Bag

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Use a thin, flexible produce bag—not a rigid bag—as this will let you see air movement clearly. Stretch the bag over the pump outlet and tape it around the base to seal it. Make sure to push most of the air out of the bag but leave some space for it to inflate.

Tip: If the bag isn’t perfectly airtight, it’s okay. The goal is to observe air movement, not a perfect vacuum.

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Step 3: Conduct the Bag Test and Observe Results

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Pump the handle slowly and observe the bag. You may see one of three outcomes:

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Scenario 1: Bag Fully Inflates and Stays Filled

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• What it means: Your pump isn’t submerged in water. The water level is below the pump intake, so no water is being drawn in.
• Solution: Lower the pump cylinder into the water by adding Drop Pipe Kits. Once submerged, pumping will resume normally.

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Scenario 2: Bag Inflates on Downstroke and Deflates on Upstroke

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• What it means: The check valve ball at the bottom is stuck or fused due to mineral build-up, preventing water intake.
• Solution:
• First, try pumping the handle down and letting it snap back up 3 to 4 times to try to free the ball.
• If that doesn’t work, remove bolts from the handle bracket, lift and drop the piston carefully to dislodge the ball.
• If still stuck, disassemble the cylinder, manually free the ball, and soak the parts in vinegar overnight to remove mineral deposits.

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Tip: Regular use (a few times a month) keeps the ball moving to prevent sticking.

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Scenario 3: Bag Does Not Inflate or Deflate

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• What it means: There is a disconnect in the pump rods — either rods have come unthreaded or the fiberglass rod is pulled out of its stainless steel fitting.
• Solution:
• Remove the handle bracket bolts and pull up on the rod.
• If it pulls up too far showing disconnected rods, uninstall the pump to find and fix the break.
• When reassembling, use Loctite on rod threads, tightening top rods while holding the bottom rods to prevent loosening.

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Summary and Next Steps

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The bag test helps you isolate the cause of a Simple Pump not pumping water:

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• Full bag inflation means no water at intake — lower your pump.
• Bag inflates/deflates indicates stuck check valve ball — try manual freeing or cleaning.
• No bag movement indicates rod disconnect — troubleshoot rod assembly.

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If you're unsure or see different symptoms, contact Simple Pump support at 877-492-8711 for expert assistance. Regular maintenance and occasional use help keep your pump working smoothly.

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Thank you for trusting Simple Pump for your water needs! Follow our support website for more tips and troubleshooting guides.