Spa cabinet or shell vibrates excessively and makes loud rumbling noises when pumps run.

Safety first: Turn off power before adjusting pump mounts.

• Check for air: Bleed air from the pump by loosening the union slightly until water flows, then retighten. Air can cause cavitation and noise.
• Inspect mounts: Ensure the pump is securely bolted to its base and that rubber isolation feet are intact.
• Align plumbing: Check that plumbing is not forcing the pump into a twisted position. Loosen unions, realign, and retighten if necessary.
• Add padding: If cabinet panels vibrate, add foam or rubber padding at contact points to reduce noise transmission.