Controller shows LOP or LOW PRESSURE; system shuts off solar pump to protect panels.

Safety: Turn off power to pumps before opening any pump lids or unions.

• Check for air in pump: Look at the main pool pump and solar booster pump lids. Excessive air bubbles or loss of prime indicates a suction leak.
• Clean baskets: Turn off power, relieve pressure, and remove the pump strainer basket. Clean out debris and reinstall the lid with a lubricated O-ring to ensure a good seal.
• Inspect unions and fittings: Tighten suction-side unions and check for cracks in fittings leading to the Fafco solar feed line.
• Check pressure switch: Locate the low-pressure switch on the Fafco solar manifold. Inspect wiring and ensure the switch is not clogged with debris. Gently clean the port if accessible.
• Restart and monitor: Restore power, prime the pump, and watch the pressure gauge. If LOP persists with good pressure, the pressure switch may need replacement.