Pump emits a loud rattling or clattering noise while running.

Safety first: Unplug the pump before tightening or opening anything.

• Check for air leaks: Inspect suction hose connections, pump lid O‑ring, and hose clamps. Tighten and replace seals as needed. Excess air can cause rattling cavitation.
• Secure mounting: Ensure the Bestway pump is firmly attached to its base or platform. Tighten any loose screws or bolts.
• Inspect impeller: Remove the wet end cover (if accessible) and check that the impeller is firmly attached to the motor shaft and not cracked.
• Test after reassembly: Prime the pump fully with water and run again. If rattling persists, internal plastic components may be damaged and the wet end may need replacement.