This is a Sundance Marin from about 2000

I just got this tub set back up after being in storage for several years. I got it all set up last night and powered it up, no leaks and all the motors and heater seem to work just fine. I set the heat to 100 F

this morning I checked it and it had come up to 89 F but had a MSG on the screen of OH which means overheated water.
It did not feel overheated according to my touch so I powered it down and back up. at this point the OH went away but now I have the FLO MSG flashing.

All the pumps and plumbing are working just fine including the recirculating pump. I can crank the main pump to high and watter flows just fine.

Do you think there is an air bubble or something like that in the system causing the issue or do you think it might be a sensor. If you think its a sensor are there any good resources that would help me to diagnose the sensors?

I did try the two methods for fixing the problem 1 - forcing water in to the filter take up pipe with a garden hose 2- let air out of the valves on the edge of the tub that divert the flow to different jets.

Thanks

Let me know what you think
Thanks

One more detail. It seems to be stuck at 89 F it is not cooling or warming.

Just an update, I found the sensor and manually activated it with a screwdriver. I measured resistance at the connection to curcuit board and it measured open at all times.

I assume it should measure compleatly closed if water iw flowing - it is - I can see the sensor arm mooving all the time and small bubles mooving in the tube.

I assume that its the switch at this point unless some of you with more experiance tell me otherwise.

Let me know.

Thanks

I replaced the flow switch and that fixed the problem. I have included several pics that show the new switch and also where the connector is located on the controller board.

Well I spoke to soon. It did not fix the issue. now I have an OH and a FLO mssg alternating. I am going to start a new thread.

Just to wrap this whole thing up, I have finally fixed it and its been working flawlessly for about a week now. At the end of the day what was really wrong was that I had a defective FLO sensor and a defective temperature sensor. the way I checked the Flo sensor was to pull the pins out of the connector on the main circuit board and check to see if the Flo sensor was "sensing" Its really just a switch that closes when there is a certain level of water Flo. so just take an ohmmeter and activate the switch manually to see if the switch closes. If not then its bad. The temp sensor was about as easily done ( I could have saved myself a bunch of time if I had checked all the sensors at the same time). But all you do is get yourself a thermometer and measure the water temp and both of the temp sensors should read very close to the same for resistance for a given temp. there is a chart that I got from http://www.spaandpoolsource.com/sundanc... ostic.aspx that tells you exactly what resistance you should see at what temp. In my case the temp sensor was way off so the over limit temp sensor kept kicking the tub off at 107F and telling me the tub was overheated - It was!! Getting the temp sensor out was a small challenge but not to bad. You just had to carefully pick the insulation away that surrounded it. Make sure you don't knick anything ells that is buried in the insulation. And yes when you pull it out water will flow out of the mounting hole, Just be ready with the new one and you wont loose to much. I coverd the motors and channeled the water away with the cover of the filter I hope this helps