Gecko · in.xe and MSPA / SSPA packsFix soon

FLC on a Gecko hot tub: flow switch stuck closed

The system sees the pressure or flow switch closed when the pump is off, which should not happen. The heater is locked out until it is fixed. The water is safe, but the tub will not heat.

Also shown as: FL C, flow closed

Most likely causes

  1. 1Pressure switch stuck or out of adjustmentmost likely
  2. 2Debris or scale holding a flow switch paddle closedcommon
  3. 3Switch wiring shortedless common
  4. 4Circuit board faultless common

What to try, in order

  1. Turn the tub off at the breaker for 30 seconds, then back on.
  2. Clean the filter and confirm the water level, in case the code was misread and is really FLO.
  3. Note the pack model from the label on the control box.
  4. If FLC returns, have the pressure or flow switch tested and replaced.

FLC questions

What is the difference between FLO and FLC?

FLO means no flow is detected when the pump is running. FLC means flow is detected when the pump is off, which points at the switch itself.

Will cleaning the filter fix FLC?

Rarely. FLC is nearly always the switch or its wiring, not the filter.

Related codes

Gecko AOH · Equipment bay too hotGecko FLO · No water flow detectedGecko HL · High limit trippedGecko Hr · Internal hardware errorGecko OH · Spa water overheatGecko Prr · Temperature probe problemGecko UPL · No configuration software

General guidance. Follow your manufacturer's instructions; anything inside the control box is work for a licensed professional. Updated October 5, 2026.