Control panel displays FLO or FL, pumps will not run or heater will not turn on, spa may shut down shortly after startup.

Safety first: Turn off power at the GFCI breaker before opening any equipment bay or touching wiring. Never run the spa without adequate water level.

• Check water level: Ensure the water level is above all skimmer openings and filter intakes. Top up if needed.
• Clean or remove filter: Remove the Arctic Spas filter cartridge from the skimmer or filter canister. Rinse thoroughly with a garden hose from top to bottom. For testing, try running the spa briefly without the filter to see if the FLO code clears.
• Bleed air from lines: After a refill, air can be trapped. Loosen the union on the circulation pump or main pump (just enough to let air hiss out) until water begins to seep, then retighten. Restore power and see if circulation resumes.
• Verify valves are open: In the equipment bay, confirm all slice/knife valves on either side of the pumps and heater are fully pulled up/open. A partially closed valve will cause FLO.
• Check circulation pump operation: With power restored, listen and feel for vibration at the Arctic Spas circulation pump. If it hums but does not move water, it may be seized or air-locked. If it is silent and not running when it should, the pump or its capacitor may have failed.
• If FLO persists: Replace the filter cartridge if it is old or collapsed. If there is still no flow and valves are open, the circulation pump assembly likely needs replacement.