AO Smith pool pump emits a loud banging or knocking noise when starting or stopping.

Safety First: Turn OFF power before tightening mounts or adjusting valves.

• Secure pump: Check that the AO Smith motor and pump base are firmly bolted to a solid pad. Tighten loose mounting bolts.
• Operate valves slowly: Open and close return and suction valves gradually to prevent sudden pressure changes.
• Bleed air: Use air relief valves on the filter and high points in the system to remove trapped air.
• Consider water hammer arrestors: In severe cases, consult a professional about adding water hammer arrestors or reconfiguring plumbing to reduce shock.