Pump is running but the pump basket is full of air and water flow is intermittent.

Safety: Turn off power before opening the pump lid.

• Inspect and lube lid O-ring: Remove, clean, and lubricate the Zodiac pump lid O-ring with silicone lube. Replace if cracked or flattened.
• Tighten unions: Hand-tighten suction-side unions at the pump and valves. Do not overtighten to the point of cracking.
• Check for visible leaks: With the pump running, look for air bubbles or water seepage at joints. You can carefully apply soapy water to joints and watch for it being sucked in.
• Skimmer test: Block off one suction source at a time (e.g., close main drain or skimmer valve) to see if the air disappears, helping locate the leak.

Underground suction leaks or cracked fittings may require professional leak detection and repair.