'solid' FLO message on Sundance Spa

[alleethia]

Can anyone offer any further recommendations to troubleshoot and hopefully resolve the problem we are experiencing? We have an Optima spa which is about 9 years old. We've had to replace the circ pump twice (by professional spa service co.) in less than 2 years, when the original lasted approx. 7 years. The latest failure occurred about 2 weeks ago. The fuse had blown and once replaced we noted the circ pump had failed. It was replaced and seemed to operate fine so the repairman left. We turned up the temp and the next morning when we went out to use the spa we noticed the 'solid' FLO message. We're not exactly sure when it came back on, but here's what we've tried so far:
1. We reset the power and initially there's no FLO message. However after several minutes it reappears.
2. We removed the filter, reset the power. Spa operates for over an hour without the FLO message but eventually reappears.
3. We place a water hose where the filter normally sits and FLO message disappears. Once the hose is removed, the FLO message reappears (approx. 20 minutes after the hose is removed).
4. I tried gently tapping the FLO switch in case this would help open the switch but no change perceived.
Right now the spa is powered off.

[clover]

There are two seperate "Flo" messages, one that is "flashing Flo" and the other is a "solid Flo".

Flashing Flo indicates the flow switch is NOT closing, (keep in mind water flow is what closes the magnetic switch inside the plumbing).  This is commonly caused by restricted water flow, starving water supply when filter gate does not drop causing cavitation, a dirty filter, a bad circulation pump,
Solid Flo indicates the switch DID NOT open when the water motion stopped.  The flow switch is transparent and you can see the "sail" switch inside the fitting.  You should be able to see it close and open.  When it opens, you need to measure the resistance when open to see what the circuit board sees.  It should be OL or infinity.  IF in fact it reads resistance when open, your flow switch is bad.  Your circuit board does not "KNOW" it is open and goes into self defense to protect the spa heater system with a SOLID FLO message.   

The switch operates a motion switch comprised of a solid center stem and a metal spring loaded vane that moving water moves to come in contact with the solid center stem making the magnetic connection.

Circulation pumps are a common repair / replacement item. 

The Flo switch is operated by the hydraulics of the water flow. 

You should have your service man return to verify proper water folw conditions.

[SerjicalStrike]

Is anything running when the solid FLO appears?

If yes, you probably have a stuck circ pump relay
If no, you more than likely have a bad flow switch.

[alleethia]

Circ pump runs while the 'solid FLO' message appears. How can I test the circ pump relay? I will try to research it online but would certainly appreciate any further instructions you might offer.

[clover]

Is your 'flo" message actually "FLO2"?  Can you attach a picture of the inside of the circuit board load box.  IF NOT, can you tell me how many wires are on the second terminal strip from the bottom right corner.  The first one is for the ozone, the second is for the circ pump and so noted on the inside door diagram.

Do you have 1 or 2 wires connected to the circuit board, if 1 where is the other wire connected? 

A picture may reveal the problem and is worth a thousand words.   

[SerjicalStrike]

Your last circulation pump that was replaced probably took out that relay when it went bad.  It is a fairly easy fix for someone that knows how to replace a relay. 

[clover]

Your last circulation pump that was replaced probably took out that relay when it went bad.  It is a fairly easy fix for someone that knows how to replace a relay.

Serj, the circ pump is running even though they have a "solid flo", which I believe to be a "FLO2" message.  With a solid flo nothing should work.  You may be suggesting the relay is stuck "closed", but I think not.  I do not believe it to be the relay, I would "assume" (that's were we all go wrong)the service man would have detected that. 

I believe the pump is running with a steady 110 v supply, eventually causing failure.

Alleethea, to check the relay you will need a voltage meter.  If you have one available, I will provide further detail. 

[SerjicalStrike]

Your last circulation pump that was replaced probably took out that relay when it went bad.  It is a fairly easy fix for someone that knows how to replace a relay.

Serj, the circ pump is running even though they have a "solid flo", which I believe to be a "FLO2" message.  With a solid flo nothing should work.  You may be suggesting the relay is stuck "closed", but I think not.  I do not believe it to be the relay, I would "assume" (that's were we all go wrong)the service man would have detected that. 

I believe the pump is running with a steady 110 v supply, eventually causing failure.

Alleethea, to check the relay you will need a voltage meter.  If you have one available, I will provide further detail.

The pump is running when it should not be.  It does not matter if the error message is FLO or FLO2.  The issue is that the relay is stuck closed, causing the pump to run when it is not supposed to.  FLO means the flow switch is closed when it should be open.  FLO2 means that this problem has been detected at startup.  Same issue though.