Digital display shows E03 and pump will not prime; pump may run but no water flow is established.

Safety first: Turn off power at the breaker before opening the pump lid or unions.

• Check pool water level: Ensure the water level is at least halfway up the skimmer opening so the skimmer weir does not draw in air.
• Inspect and lubricate lid O-ring: Remove the AquaFlo pump lid, clean the lid O-ring and sealing surfaces, and apply a thin coat of pool-safe silicone lubricant. Replace the O-ring if cracked or flattened.
• Fill pump strainer housing: With the lid off, fill the pump basket housing completely with water using a hose. Reinstall the lid securely and hand-tighten.
• Check suction-side unions and valves: Inspect the suction union at the pump inlet and any suction valves for looseness or air bubbles when the pump starts. Tighten unions and ensure valve stems are not leaking.
• Clear suction line blockage: Remove the pump basket and check for debris. If flow is still not established, backwash or clean the filter and use a drain king or plumbing snake from the skimmer line to clear obstructions.

After correcting air leaks and blockages, restore power and attempt to prime again. If E03 persists, the flow sensor or controller may be misreading and require service.