Safety: Isolate power at the breaker before opening the pump lid or unions.

Inspect pump lid and O-ring: Remove the clear lid, clean the sealing surfaces, and inspect the O-ring for flat spots, cracks, or stretching. Replace if damaged and apply a thin coat of silicone-based lubricant.
Tighten lid: Refit the lid and hand-tighten evenly. Do not overtighten with tools as this can crack the lid.
Check suction valves: Ensure all suction valves (skimmer, main drain, vacuum line) are fully open. Partially closed valves can cause loss of prime.
Check for visible air leaks: While the pump is trying to run, look for air bubbles under the lid or water drips around unions. Tighten unions on the Hurlcon pump inlet and outlet by hand.
Re-prime: Fill the pump housing with water, refit lid, restore power, and start the pump. Watch for a solid column of water with minimal air bubbles.

If F2 continues, a technician should pressure-test the suction line and inspect the mechanical seal and Hurlcon wet end for internal air leaks.

Pump stops shortly after starting and displays F2 on the Hurlcon controller.

Possible Causes