Display shows FLO or FL, heater will not turn on, jets may run briefly then stop, water is not heating.

Safety first: Turn off power at the GFCI breaker before opening any access panels or touching internal components.

• Check water level: Ensure the spa is filled to the proper level (above all suction fittings and at least halfway up the skimmer).
• Clean or remove the filter: Remove the filter cartridge used in Lifesmart Spas (typically a screw-in or drop-in cartridge). Rinse thoroughly with a garden hose from top to bottom. For testing, run the spa briefly without the filter to see if the FLO code clears. If it does, replace the filter.
• Bleed air from the system: After refilling, loosen the union on the circulation pump or open any bleed valve near the heater until water flows steadily, then retighten. This removes air locks that can trigger FLO.
• Check circulation pump operation: With power restored, verify that the small circulation pump is running (you should feel vibration and see gentle water movement at the heater return). If it hums but does not move water, the impeller may be jammed or the pump failing.
• Inspect the flow/pressure switch: Locate the flow switch in the plumbing near the heater tube. Check that the wires are firmly connected and that there are no kinks in the hoses. A stuck or failed switch may need replacement.
• If FLO persists: Replace the filter with a new OEM-compatible Lifesmart filter and, if needed, replace the flow switch or circulation pump. If you are not comfortable working with plumbing and electrical, contact a spa technician.