Display shows “LF”; spa shuts down heater after extended low-flow condition.

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.

Possible Causes

Severely restricted filters, Failing circulation pump, Blocked heater manifold, Air leak on suction side of circulation pump

Safety first: Turn off power at the breaker.

Remove filters completely: Run the spa without filters to see if LF clears. If it does, replace the filters.
Check for suction air leaks: Inspect the circulation pump suction fittings and unions for air bubbles or water drips when running.
Feel pump temperature: A very hot SilentFlo pump that is not moving water is likely failing internally and should be replaced.

If LF persists with clean filters and good plumbing, schedule a technician to replace the circulation pump and inspect the heater.

Hard 4/5

SilentFlo 5000 Circulation Pump

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