Sundance CAMEO FLO error

[mathieu]

First time user of spa. Bough the house and spa was there. So I empty it, clean it, fill it, treat water etc.

Everything is fine, I used it twice. First time I used it the FLO message during the time pumps were functionning and then it disapeared 2-3 minutes later. Second time I used it FLO message appears again when the pumps are functionning. This time I close the pumps and the FLO is still there (Flashing between temperature and FLO).

I hear the pump "functionning" and tried to remove my filter like they say in the documentation (switch off, remove filter, wait 2-3 minutes and boot again) to make sure it wasn't a dirty filter. FLO message is still there. I also read some stuff about air lock so I tried to push water in the hole where the filter attach, no luck again. Didn't really seems to work very well anyhow.

Then I don't know how or why, but I found out that when I turn my waterfall valve to fully open, I don't have the FLO anymore and heater comes back online. And I tried it more than once. I tried almost closed, half, almost open and it only seems to work when it's fully open.

Does anyone has an idea on what could be my problem?

Heater and pump seems like they worked fine until now so I somehow doubt it could be the problem.

[Nessuno]

You didn't mention what year your sundance is, but I have a 2000. If they haven't changed their design much, it works like this. The heater will only work if the flow switch is closed. The flow switch resides in a tee housing that is inline with the heater. It is used to protect the heater from a meltdown by keeping the heater from turning on if there is no flow into said heater. I/we have 2 ways to close that flow switch. The circulation pump is inline with the heater and flow switch and generally operates 24/7 (it can be programmed to rest at times). It feeds water through the heater and flow switch. If the circ pump fails, I can turn on my 2-speed jet pump which is used for the filtration cycles as it is also inline with the circ pump, heater, and flow switch. The jet pump sends water through the circ pump, heater, and flow switch.

A dirty filter can limit flow enough to not close the switch, but you have already tested that theory by removing the filter.

If your jets are pumping water then it is not an airlock either.

You mention that when you open the waterfall valve the FLO goes away and the heater turns on. This indicates that the flow switch is good and your circ pump is probably bad and the jet pump is forcing water through the heater and flow switch. I'm not sure of your tub's design, but I'm guessing turning the Waterfall valve diverts water to/from the heater and flow switch pathway? With that valve partially closed, there's not enough pressure to close the FLO switch?

Until you can replace that circ pump, you might want to program your filtration cycle (I assume it uses the same jet pump as the waterfall) for 24/7 during any cold spells. Probably a good idea to test the voltage to the circ pump also.