Puzzled with another FLO error problem on sundance optima

[Oli_G]

Hello all,

Have a good one for the spa gurus !

I have the typical flashing "FLO" error on my Sundance optima 2001, but I think it have an untypical cause...

First, for the tub history : it was bought in 2002, but was only used in summers, winterized every year. 3 years ago my dad, who is the original owner, found the FLO error code on the display and was told the problem was the circulation pump. Having not used it for a while, he didnt have it repaired and let it sat unused since. Recently I bought the family house and the defective spa came with it. I'm now trying to get it back running the DIY way I'm used to 

So, refilled it this week and started it, FLO error is not gone by magic. When jet pumps where off, flow switch was completely open at 45 degree, and the circulation pump was not not running. Knowing it was supposed to run 24/7, I opened the pump, cleaned it from hard water depot, reconnected the ground wire which was unseated probably because of vibration and putted it back in the tub. That did the trick and now when I power up the tub with jet pumps off, the circulation pump is working correctly, as I hear it and I feel flow at the heat/ozone output port. The flow switch is now at like 22.5 degree but not closed...

What is very strange is that if I power on the 2 speed jet pump on lower speed, whose output split to the jets and to the circulation pump input, the flow switch close completely and the heater starts normally! So flow switch seems functionnal. It seems the extra flow to the circulation pump input is enough to close the switch...

I tried with and without filter on.

So, I think the circulation pump runs normally, I think the flow switch works as it should, and I think my filter is not clogged.

What's happening here? Is it possible than the circulation pump is partially air locked ? Should I unscrew the flow switch to bend a bit the tab? Is it possible to have a clogged heater wich is between the circ pump and the flow switch?

If you have any clue, I would appreciate !

Thanks

[Nessuno]

I have a 2001 Sundance Cameo 850 series very similar to yours. I think you've nailed the possible causes on the head. 1. The circ pump is weak. 2. The flow switch is hard to close than it should be. 3. Something is restricting water flow whether it be the filter or something in the heater. As you mentioned, you could try to bend the prongs on the flow switch a tad to see if they will close easier. That's the cheap solution up front. I do suspect the circ pump since it wasn't running initially. Maybe it's not producing water flow the way it should. A flow meter would be great to use if you could obtain one. Clogged heater? Never heard of one. I have heard of hoses gettting gunked up.

[Oli_G]

Thanks for the answer HomePC, I was no longer expecting one.

You where right in your suspicion : The circ pump was the culprit, as it was working, but barely producing flow. Tested it with wet end removed and it was turning at like 50 rpm while it should have been 3450 rpm... I replaced it with the new Laing E10 pump and that fixed the FLO problem.

[Nessuno]

Glad you got it working. I have also gone to Laing pumps. I have had problems where my heater developed a leak and it would drip right on top of the circ pump causing it to eventually fail. I have finally reworked the plumping and moved the circ pump to the right next to the 2-speed pump. Works well.

[SEWSPCL]

I have an 89 Sundance spa worked great for years but kept getting the flow error. 2004 bought a new circulation pump and still getting solid  flo error.  hrsWatched a YouTube video and it said to bypass the flow switch by putting a paperclip in both ends. I did that and it ran great for a day. But still get the flow error. Temperature is reading 34 degrees even though Spa is hot so I'm suspecting thermometer? Any thoughts?

[Nessuno]

Interesting. With the Flow Switch shorted, and you still get the "FLO" error, I would suspect the logic board. That can lead to a potential meltdown with the heater also (if you're tub is still similar to my 2001 Sundance Cameo), if no water is pumping through the heater core and it is trying to heat (Experience speaking here, I accidentally had a meltdown that turned my plastic heater housing into a goey mess.). 

You probably have a thermostat which is reading wrong. There is also a high-limit temperature sensor but that is a fail safe device I do believe. 34degrees Celsius is 93.2 Fahrenheit. could your board be set to Celsius?

[Nessuno]

Follow Up for anyone researching circulation pumps. My Laing pump is still working. No problems.