FLC
Tuff Spas
Flow Switch Closed When It Should Be Open
Display shows FLC or FLOC; heater is disabled and spa may cycle pumps trying to clear the fault.
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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 paddle or reed, Shorted flow switch wiring, Miswired flow switch at control pack, Control board input fault
How to Fix / Troubleshooting
Safety: Turn off power at the breaker before inspecting wiring or sensors.
- Step 1 – Inspect flow switch body: Locate the flow switch in the plumbing near the heater. Check for physical damage, leaks, or signs of overheating.
- Step 2 – Check wiring: Follow the cable from the flow switch to the control pack. Ensure it is not pinched, cut, or chewed. Reseat the connector on the control board.
- Step 3 – Basic test: With power off, disconnect the flow switch from the board. Restore power briefly. If the FLC code changes to FLO or a different flow error, the switch is likely stuck closed and should be replaced.
- Step 4 – Replace flow switch if needed: Drain water below the level of the flow switch or close slice valves. Remove the old switch, install the new Tuff Spas-compatible flow switch in the same orientation (arrow in direction of flow), and reconnect wiring.
If a new flow switch does not resolve FLC, the control board input may be defective and the spa pack may need professional evaluation or replacement.
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Repair Difficulty
Hard
4/5
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