Control panel displays F1 and spa functions are disabled or intermittent.

Safety first: Turn off power to the spa at the main breaker before opening any panels or touching internal components.

• Check water level: Ensure the water level is above all jets and at least halfway up the skimmer. Low water can cause low flow.
• Clean the filter: Remove the Hanscraft cartridge filter from the skimmer or filter housing. Rinse thoroughly with a garden hose from top to bottom until water runs clear. Reinstall the filter and ensure it is seated correctly.
• Open all valves: Verify that all Hanscraft slice valves or ball valves on the suction and return lines are fully open. A partially closed valve will trigger low-flow errors.
• Bleed air from the system: With power OFF, loosen the union on the circulation pump or use the bleed screw (if present) to release trapped air until water seeps out, then retighten. Restore power and see if the error clears.
• Test circulation pump: Turn power back on and listen for the circulation pump. If it hums but does not move water, the pump may be seized or failing and should be replaced.

If F1 persists after cleaning the filter and bleeding air, the circulation pump or flow sensor may need professional diagnosis and replacement.