FLO error on 1998 Sundance Calypso

[dkamm]

I have a FLO error that is very reproducible.Here are the details of what I have:
1998 Sundance Calypso with Sentry 750/850 controls.
The actual board is a 6600-027

I have all ready replaced the flow switch and the temperature sensor near the filter (not in the heater) because the tested bad or looked in bad shape.
1) To reproduce the error I turn on the power and up the temperature to a few degreees above the current temp. The flow light is on, the heat light comes on, the jets light is blinking, and there is water flow coming out of the circulation pump (small pump) jet near the light, and water flow coming out of the pump1 jets.
2) Once the temperature has been reached the heat light goes out in roughly 5-10 sec. Within the next minute pump1 shuts off, the jets light goes out, and the water flow to the pump1 jets stop. Within about 10 seconds after that the FLO error comes up. At this point there is still water flow coming out of the circulation pump jet near the light and I can feel the circulation pump running.
3) At this point the control pad switches between the current temp and FLO. If I disconnect one of the flow switch wires for a few seconds and reconnect it all is back to normal and I can increase the temperature and repeat the whole scenario.
4) If I disconnect the flow switch wires and connect a jumper between the two wires I get the same results which I assume dismisses the flow switch as the problem. The switch test correctly as well unlike the old switch.

I can't seem to find any logic diagrams, schematics, or technical manuals for the actual circuit board so that I can figure out what may be causing this. Does anyone have any ideas?

[MaryH]

To properly test the flow switch you need to take a continuity test by removing the two wires from the sensor plug at the circuit board after turning power off the the spa. You can use a unbent paper clip to depress the tabs on the wires to remove them. You then turn power back on to spa and run the pump, if you have continuity while the pump is running and paddle should be closed then switch is good. If you get and infininte reading then switch is not closing or defective. You said you replaced the flow switch, you want to make sure that the alignment arrow on the flow switch is pointing to the flow switch outlet. Sometimes they can be off and cause the switch to not close. If all test good and still getting the FLO error then yes it could be the circuit board. You didn't mention anything about removing the filter, you may want to try that first.

[dkamm]

Thanks, I did test those items before, but went back and double checked again. So the flow switch is installed the correct way and it shows continuity when the circulation pump is running. I did also try running it without the filter and I get the same error. I am not understanding why the flow light will stay on even when the FLO error is showing. I guess I didn't mention that before. It is almost like it is reading the flow switch output fine, but something else is causing it to have a FLO error.