Display shows LO and pump will not run or runs intermittently.

Safety first: Turn off power at the breaker and lock it out if possible. Electrical work should comply with local codes; contact a licensed electrician if unsure.

• Verify supply voltage: Check the nameplate on your Hayward variable-speed pump (e.g., 230V). Use a multimeter at the pump's terminal block to confirm voltage matches the rating.
• Inspect wiring connections: With power off, remove the electrical cover on the pump. Tighten all terminal screws and check that wires are fully inserted and not burned or discolored.
• Check wire gauge and run length: Ensure the wire size matches Hayward’s installation manual for the distance from the breaker to the pump. Long runs with small gauge wire can cause voltage drop.
• Inspect external controls: If the pump is controlled by a Hayward automation system (e.g., OmniLogic, ProLogic), inspect the relay/contactor feeding the pump for pitting or overheating.
• Test again: Restore power and monitor the voltage while the pump starts. If LO persists with correct voltage, the internal drive electronics may be failing and the drive assembly should be serviced or replaced.