FLO Error

[szelik]

I currently own a Sundance Optima hottub (probably 2005) and noticed a FLO error. I did replace the flow switch and replaced the filter to no avail. I also tried running it without the filter in it and left it powered down for 30 mins as well. All pumps seem to work when I push the buttons to turn them on. My father (who knows way more about electricity than I) ran a voltmeter on the heater and that appears to be okay, however, the tub is not producing heat. I am curious what the piece circled in red in my picture is. It connects from the fliter to the heater an I am thinking this may have went up. Any input is greatly appreciated.

[clover]

First, locate the flow switch in a transparent pvc "Tee" in the plumbing leaving the heater and crossing the upper section of the right service panel.  You can see the operation of the sail switch as water moves through the switch and you should see it close.  If it is not closing, you don't have water moving through the plumbing.  When water moves through the Tee is closes the magnetic switch.  YOUR switch is not closing and is the reason why you are getting the message.

Secondly, check the circ pump that drives the water through the heater system that will not work until the flow switch closes, signalling the flow of water that allows the heater to work.

Is the pump hot or cold to the touch.  Check voltage going to the circ pump.  It is likely to be a bad circ pump.