Spa cabinet or shell vibrates excessively and makes loud rumbling when jets are on high

Safety first: Turn off power before tightening any hardware or touching pumps.

Steps to reduce vibration:

• Bleed air: Remove air from the pump as described in previous steps to reduce cavitation.
• Check mounting hardware: Ensure pump mounting bolts are snug but not overtightened, and that rubber isolation pads are in place under the pump feet.
• Inspect plumbing alignment: Verify that rigid PVC plumbing is not forcing the pump into a twisted position.

When to call a technician: If vibration persists or plumbing needs to be reworked, professional service is recommended.