Display shows FLC or FL2, heater disabled, sometimes occurs intermittently

Safety first: Turn off power at the GFCI breaker before working on plumbing or wiring.

Diagnosis steps:

• Inspect flow switch orientation: Locate the flow switch near the heater. Ensure the arrow on the body points in the direction of water flow. If installed backwards, correct the orientation.
• Check for debris: Remove the flow switch (with spa drained below that level or lines plugged). Inspect the paddle or internal mechanism for scale or debris that could hold it closed. Clean gently and reinstall with new o-rings if needed.
• Inspect wiring: Follow the flow switch wires to the control pack. Look for pinched, cut, or melted insulation. Ensure the connector is firmly seated on the correct header.
• Test switch (if you have a meter): With no pump running and power OFF, disconnect the switch and measure continuity across the contacts. It should be open (no continuity) when there is no flow. If it reads closed, the switch is stuck and should be replaced.
• Replace flow switch: Install a compatible Dream Maker/Balboa/Gecko flow switch if the original is faulty. Do not bypass the switch for normal use.
• Control board check: If a known-good switch still gives FLC, the control board input may be shorted. Have a spa technician evaluate and replace the board if necessary.