I have a Caldera Geneva Series spa from the early 2000s. My heater and circ pump appear to work fine but once spa gets up to set temperature the circ pump turns itself off and not soon after I get a FLO indication. The circ pump was just replaced because it was excessively hot and loud, but I was experiencing this problem even before replacement. Spa set for standard operation.

For example: Filled up spa today. Turned it on, circ pump was putting out good amount of hot water. Spa heated up to 101 (the set temperature) but soon after it got there, it shut off and indicated FLO. If I reset the breaker, spa will come back on and I can adjust the temperature upward. If I try to move temperature below 101, spa heater light automatically goes off, pump stops, and after awhile will show FLO.

Any help with this will be greatly appreciated.

Gary Burghart

Most likely a problem with the pressure switch. For some reason, I've noticed that the early Watkins owned Calderas would heat up initially and then give the flo error code if the pressure switch is bad.