The pump runs but there is no water flow; the pressure gauge on the filter reads zero or very low.

Safety: Turn off the pump before opening the lid or valves.

• Check water level: Ensure the pool or balance tank is full enough to cover skimmers or feed the suction line.
• Inspect lid O-ring: Remove the clear Certikin pump lid, clean the O-ring and sealing surface, apply a suitable silicone-based lubricant, and refit. Replace the O-ring if cracked or flattened.
• Prime the pump: Fill the pump strainer housing completely with water, reinstall the basket and lid, then restart the pump and watch for air clearing from the system.
• Verify suction valves: Confirm all necessary suction valves are open, and that any Certikin non-return valve is not stuck closed.