Display shows FLC or FL2; spa may not heat and may run pumps unexpectedly

Safety: Turn OFF power at the GFCI breaker before servicing.

• Inspect flow switch orientation: Locate the flow switch near the heater. Ensure the arrow on the body points in the direction of water flow and that it is installed horizontally as specified.
• Check for debris: If plumbing allows, remove the flow switch and inspect the paddle or plunger for debris or scale buildup. Clean gently and reinstall with new gaskets if needed.
• Inspect wiring: Follow the flow switch wires to the control pack. Look for crushed insulation, rodent damage, or water intrusion at the connector. Reseat the connector firmly.
• Continuity test: With the spa OFF and the flow switch removed from plumbing, use a multimeter to check continuity across the switch terminals. It should be open (no continuity) when no flow is present. If it reads closed, the switch is stuck or shorted and must be replaced.
• Replace flow switch: Install a new Bullfrog-compatible flow switch, ensuring correct orientation and tight, leak-free unions. Reconnect wiring.
• Reset and test: Restore power and verify that FLC/FL2 clears and that the spa heats only when the circulation pump is running.

If the new flow switch behaves the same, the control board may have a shorted input; professional diagnosis is required.