FLC
Master Spas
Flow Switch Closed When It Should Be Open
Display shows FLC or FL2 and spa may shut down heater, sometimes pumps run continuously
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Stuck flow switch contacts, Shorted flow switch wiring, Incorrect flow switch installation, Control board input fault
How to Fix / Troubleshooting
Safety first: Shut off power at the GFCI breaker before working on wiring.
- Inspect flow switch wiring: Locate the flow switch near the heater and follow its wires to the control pack. Look for pinched, cut, or shorted wires.
- Check for debris: Remove the flow switch (with spa drained below that level) and inspect the paddle or plunger for debris or scale buildup. Clean gently and reinstall with new o-rings if needed.
- Verify orientation: Ensure the flow switch is installed in the correct direction (arrow with water flow) and not upside down.
- Test switch: With the switch removed and dry, check continuity across the terminals. It should be open (no continuity) with no flow. If it reads closed, replace the flow switch.
- Board check: If a new switch still shows FLC, the control board input may be shorted and the control pack may need replacement by a technician.
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Repair Difficulty
Medium
3/5
Required Part
Flow Switch Assembly
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