Air bubbles or gurgling sounds are heard in the plumbing; jets may sputter.

Safety: Keep hands away from suction fittings while pumps are running.

• Top off water: Ensure water level is above all jets and suction fittings.
• Bleed air: Turn pumps on and off several times. Crack open pump unions slightly (with power off) to release trapped air, then retighten.
• Check unions: Inspect suction-side unions and fittings for looseness that could allow air to be drawn in.