Display shows FLO or FL, pumps may run briefly then stop, heater will not turn on, possible blinking heat indicator.

Safety first: Turn off power at the spa’s GFCI breaker before opening any equipment compartment or removing filters.

• Check water level: Ensure the water level is above all suction fittings and at least halfway up the skimmer opening. Top off if low.
• Clean or remove filter: Remove the filter cartridge from the filter canister. Rinse thoroughly with a garden hose from top to bottom. For testing, run the spa briefly without the filter (with the filter well open) to see if the FLO code clears. If it clears, replace the filter with a new Artisan-compatible filter cartridge.
• Bleed air from the pump: Locate the main jet pump and, if accessible, slightly loosen the pump union on the discharge side until you hear air hiss and see water seep out, then retighten. This removes air locks after draining/refilling.
• Verify valves are open: Check all slice (gate) valves around the pump and heater. The handles should be pulled up and locked. A closed valve will restrict flow and trigger FLO.
• Inspect pressure/flow switch: Locate the pressure or flow switch on the heater manifold. Check for loose wires or corrosion on terminals. If adjustable, do not overtighten the adjustment screw; only minor tweaks should be made. If the FLO code persists with good flow and a clean filter, the switch may need replacement.

If the error remains after these steps, the circulation pump or pressure/flow switch may be failing and should be tested or replaced by a qualified spa technician.