Pump display shows E13 and the unit will not start when water level is low or skimmer is drawing air.

Safety first: Turn off power before opening any part of the hydraulic circuit.

Steps to check:

• Restore water level: Ensure the pool water level is at least halfway up the skimmer opening.
• Clean baskets: Empty the skimmer basket and the Jacuzzi pump strainer basket. Remove leaves and debris.
• Check for air leaks: Inspect the pump lid O-ring for cracks or dirt. Lubricate with a silicone-based lubricant and reseat. Tighten unions on the suction side.
• Prime the pump: Fill the pump housing with water, reinstall the lid, open any air relief valves, and restart the pump.

If E13 continues with good prime and full water level, the flow/pressure sensing circuit may be faulty and require service or replacement.