Display shows FLC or FLO flashing intermittently, heater cycles on and off, sometimes runs but trips back to flow error.

Safety first: Shut off power at the GFCI breaker before touching wiring or opening the control pack.

• Clean filter and suction fittings: Remove and thoroughly rinse the filter. Inspect suction covers inside the spa for debris (leaves, hair, etc.) and clear them.
• Check circulation pump operation: With power restored, observe the small circulation pump (if equipped). It should run smoothly and quietly with a steady stream from the circulation return jet. If it surges, rattles, or stops, the pump may be weak or failing.
• Inspect flow switch wiring: Turn power off again. Open the control pack and locate the flow/pressure switch wires on the main board. Ensure the spade connectors are tight and free of corrosion. Reseat them if needed.
• Test continuity: With the spa off and drained down below the switch if necessary, disconnect the flow switch and test it with a multimeter. It should change state (open/closed) when you manually actuate the paddle or pressure diaphragm (if accessible). If it does not change reliably, replace the switch.

If the circulation pump is hot to the touch, noisy, or not moving water consistently, replacement of the circulation pump is recommended.