Flotec Pump Won't Prime – Suction Line Troubleshooting

Pump Works with Hose Prime but Fails to Draw from Pond

A Flotec sprinkler pump delivers water only when a hose feeds the priming port. Once the hose is off, flow stops. The check valve was replaced without success.

Systematic Suction Line Checks

1. Prime plug: Remove the prime plug on the pump volute. Water should be present. No water = no prime.
2. Air-tight connections: Every fitting on the suction line must be sealed. Use thread sealant on all joints.
3. Foot valve: Ensure it's installed with the flow arrow pointing toward the pump. Check for debris blocking the screen/basket. A leaky foot valve prevents priming.
4. Suction line slope: The line should slope continuously upward from the pond to the pump. Horizontal runs trap air and cause air locks.
5. Suction lift: Vertical distance from water surface to pump impeller center should not exceed 20 ft for a 2 HP centrifugal pump. If higher, a submersible pump is needed.
6. Line voltage: Measure voltage at the pump terminals while running. Low voltage reduces pump performance.

Address each item in order; the pump will prime and run once the suction line is airtight and the foot valve functions.