Spa makes loud banging or knocking noises when jets are running.

Safety first: Turn off power before tightening any hardware.

• 1. Purge air: Run jets on and off several times with all air controls open to purge trapped air.
• 2. Inspect plumbing: In the equipment bay, gently move PVC pipes to locate any that are striking the cabinet; secure with clamps or foam.
• 3. Tighten pump mounts: Ensure the jet pump and circulation pump are firmly bolted to their bases.

Persistent loud knocking may indicate internal pump issues; have a technician inspect if noise continues.